Location: BG_GiProtein @ 266e0c4f2350 / BG_GiProtein.cellml

Author:
Shelley Fong <s.fong@auckland.ac.nz>
Date:
2021-10-22 10:02:02+13:00
Desc:
Updating equations to reflect GEF action and remove wrong phosphate bindings
Permanent Source URI:
https://models.cellml.org/workspace/6f9/rawfile/266e0c4f2350878d3808446fc1e978db3dd0c9e7/BG_GiProtein.cellml

<?xml version='1.0' encoding='UTF-8'?>
<!-- Gi protein metabolism, with reactions:
 Activation (Act1 and Act2), Hydration (Hyd), Reassociation (Reassoc)
 14Oct21 with separated Phosphate binding from activation of RG and LRG-->
<model name="GiProtein" xmlns="http://www.cellml.org/cellml/1.1#" xmlns:cellml="http://www.cellml.org/cellml/1.1#" xmlns:xlink="http://www.w3.org/1999/xlink">
    <import xlink:href="units_and_constants/units_BG.cellml">
        <units name="per_sec" units_ref="per_sec"/>
        <units name="J_per_K_per_mol" units_ref="J_per_K_per_mol"/>
        <units name="C_per_mol" units_ref="C_per_mol"/>
        <units name="fmol" units_ref="fmol"/>
        <units name="fmol_per_L" units_ref="fmol_per_L"/>
        <units name="fmol_per_L_per_sec" units_ref="fmol_per_L_per_sec"/>
        <units name="per_sec_per_fmol_per_L" units_ref="per_sec_per_fmol_per_L"/>
        <units name="per_fmol" units_ref="per_fmol"/>
        <units name="fmol_per_sec" units_ref="fmol_per_sec"/>
        <units name="J_per_mol" units_ref="J_per_mol"/>
        <units name="mM" units_ref="mM"/>
        <units name="uM" units_ref="uM"/>
        <units name="mM_per_sec" units_ref="mM_per_sec"/>
        <units name="uM_per_sec" units_ref="uM_per_sec"/>
        <units name="pL" units_ref="pL"/>
        <units name="m_to_u" units_ref="m_to_u"/>
    </import>
    <import xlink:href="units_and_constants/constants_BG.cellml">
        <component component_ref="constants" name="constants"/>
    </import>
    <component name="environment">
        <variable name="time" public_interface="out" units="second"/>
        <!--Initial conditions-->
        <variable initial_value="0.0004579000" name="q_R_M2_init" units="fmol"/>
        <variable initial_value="1e-18" name="q_Gi_init" units="fmol"/>
        <variable initial_value="1e-18" name="q_R_M2Gi_init" units="fmol"/>
        <variable initial_value="1e-1" name="q_LR_M2_init" units="fmol"/>
        <variable initial_value="1e-18" name="q_LR_M2Gi_init" units="fmol"/>
        <variable initial_value="0.02" name="q_aGi_GTP_init" units="fmol"/>
        <variable initial_value="0.02" name="q_beta_gamma_Gi_init" units="fmol"/>
        <variable initial_value="0.02" name="q_aGi_GDP_init" units="fmol"/>
        <variable initial_value="570" name="q_Pi_init" units="fmol"/>
        <variable initial_value="2.2" name="q_GTP_init" public_interface="out" units="fmol"/>
        <variable initial_value="1.1" name="q_GDP_init" public_interface="out" units="fmol"/>
        <!-- mass conservation checks-->
        <variable name="R_T" public_interface="in" units="fmol"/>
        <variable name="Gi_T" public_interface="in" units="fmol"/>
        <!-- Global value-->
        <variable name="q_R_M2" public_interface="out" units="fmol"/>
        <variable name="q_Gi" public_interface="out" units="fmol"/>
        <variable name="q_R_M2Gi" public_interface="out" units="fmol"/>
        <variable name="q_LR_M2" public_interface="out" units="fmol"/>
        <variable name="q_LR_M2Gi" public_interface="out" units="fmol"/>
        <variable name="q_aGi_GTP" public_interface="out" units="fmol"/>
        <variable name="q_beta_gamma_Gi" public_interface="out" units="fmol"/>
        <variable name="q_aGi_GDP" public_interface="out" units="fmol"/>
        <variable name="q_Pi" public_interface="out" units="fmol"/>
        <variable name="q_GTP" public_interface="out" units="fmol"/>
        <variable name="q_GDP" public_interface="out" units="fmol"/>
        <!-- From submodule-->
        <variable name="q_R_M2_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_Gi_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_R_M2Gi_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_LR_M2_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_LR_M2Gi_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_aGi_GTP_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_beta_gamma_Gi_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_aGi_GDP_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_Pi_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_GTP_mGiProtein" public_interface="in" units="fmol"/>
        <variable name="q_GDP_mGiProtein" public_interface="in" units="fmol"/>
        <math xmlns="http://www.w3.org/1998/Math/MathML">
            <apply>
                <eq/>
                <ci>q_R_M2</ci>
                <apply>
                    <plus/>
                    <ci>q_R_M2_mGiProtein</ci>
                    <ci>q_R_M2_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_Gi</ci>
                <apply>
                    <plus/>
                    <ci>q_Gi_mGiProtein</ci>
                    <ci>q_Gi_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_R_M2Gi</ci>
                <apply>
                    <plus/>
                    <ci>q_R_M2Gi_mGiProtein</ci>
                    <ci>q_R_M2Gi_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_LR_M2</ci>
                <apply>
                    <plus/>
                    <ci>q_LR_M2_mGiProtein</ci>
                    <ci>q_LR_M2_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_LR_M2Gi</ci>
                <apply>
                    <plus/>
                    <ci>q_LR_M2Gi_mGiProtein</ci>
                    <ci>q_LR_M2Gi_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_aGi_GTP</ci>
                <apply>
                    <plus/>
                    <ci>q_aGi_GTP_mGiProtein</ci>
                    <ci>q_aGi_GTP_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_beta_gamma_Gi</ci>
                <apply>
                    <plus/>
                    <ci>q_beta_gamma_Gi_mGiProtein</ci>
                    <ci>q_beta_gamma_Gi_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_aGi_GDP</ci>
                <apply>
                    <plus/>
                    <ci>q_aGi_GDP_mGiProtein</ci>
                    <ci>q_aGi_GDP_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_Pi</ci>
                <apply>
                    <plus/>
                    <ci>q_Pi_mGiProtein</ci>
                    <ci>q_Pi_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_GTP</ci>
                <apply>
                    <plus/>
                    <ci>q_GTP_mGiProtein</ci>
                    <ci>q_GTP_init</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>q_GDP</ci>
                <apply>
                    <plus/>
                    <ci>q_GDP_mGiProtein</ci>
                    <ci>q_GDP_init</ci>
                </apply>
            </apply>
        </math>
    </component>
    <component name="GiProtein_parameters">
        <variable initial_value="0.744653" name="kappa_act1_Gi" public_interface="out" units="fmol_per_sec"/>
        <variable initial_value="0.0548665" name="kappa_act2_Gi" public_interface="out" units="fmol_per_sec"/>
        <variable initial_value="0.637972" name="kappa_hyd_Gi" public_interface="out" units="fmol_per_sec"/>
        <variable initial_value="108647" name="kappa_reassoc_Gi" public_interface="out" units="fmol_per_sec"/>
        <variable initial_value="0.00936036" name="K_R_M2" public_interface="out" units="per_fmol"/>
        <variable initial_value="647.502" name="K_Gi" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.0672271" name="K_R_M2Gi" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.00254079" name="K_LR_M2" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.0182483" name="K_LR_M2Gi" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.0364527" name="K_aGi_GTP" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.00343535" name="K_beta_gamma_Gi" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.00273957" name="K_aGi_GDP" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.000483503" name="K_Pi" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.0422012" name="K_GTP" public_interface="out" units="per_fmol"/>
        <variable initial_value="0.000818125" name="K_GDP" public_interface="out" units="per_fmol"/>
    </component>
    <component name="GiProtein">
        <variable name="time" public_interface="in" units="second"/>
        <!-- Physical parameters-->
        <variable name="R" public_interface="in" units="J_per_K_per_mol"/>
        <variable name="T" public_interface="in" units="kelvin"/>
        <!-- BG parameters-->
        <variable name="kappa_act1_Gi" public_interface="in" units="fmol_per_sec"/>
        <variable name="kappa_act2_Gi" public_interface="in" units="fmol_per_sec"/>
        <variable name="kappa_hyd_Gi" public_interface="in" units="fmol_per_sec"/>
        <variable name="kappa_reassoc_Gi" public_interface="in" units="fmol_per_sec"/>
        <variable name="K_R_M2" public_interface="in" units="per_fmol"/>
        <variable name="K_Gi" public_interface="in" units="per_fmol"/>
        <variable name="K_R_M2Gi" public_interface="in" units="per_fmol"/>
        <variable name="K_LR_M2" public_interface="in" units="per_fmol"/>
        <variable name="K_LR_M2Gi" public_interface="in" units="per_fmol"/>
        <variable name="K_aGi_GTP" public_interface="in" units="per_fmol"/>
        <variable name="K_beta_gamma_Gi" public_interface="in" units="per_fmol"/>
        <variable name="K_aGi_GDP" public_interface="in" units="per_fmol"/>
        <variable name="K_Pi" public_interface="in" units="per_fmol"/>
        <variable name="K_GTP" public_interface="in" units="per_fmol"/>
        <variable name="K_GDP" public_interface="in" units="per_fmol"/>
        <!-- Input from global environment-->
        <variable name="q_R_M2_global" public_interface="in" units="fmol"/>
        <variable name="q_Gi_global" public_interface="in" units="fmol"/>
        <variable name="q_R_M2Gi_global" public_interface="in" units="fmol"/>
        <variable name="q_LR_M2_global" public_interface="in" units="fmol"/>
        <variable name="q_LR_M2Gi_global" public_interface="in" units="fmol"/>
        <variable name="q_aGi_GTP_global" public_interface="in" units="fmol"/>
        <variable name="q_beta_gamma_Gi_global" public_interface="in" units="fmol"/>
        <variable name="q_aGi_GDP_global" public_interface="in" units="fmol"/>
        <variable name="q_Pi_global" public_interface="in" units="fmol"/>
        <variable name="q_GTP_global" public_interface="in" units="fmol"/>
        <variable name="q_GDP_global" public_interface="in" units="fmol"/>
        <!-- Output to global environment-->
        <variable initial_value="1e-16" name="q_R_M2" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_Gi" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_R_M2Gi" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_LR_M2" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_LR_M2Gi" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_aGi_GTP" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_beta_gamma_Gi" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_aGi_GDP" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_Pi" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_GTP" public_interface="out" units="fmol"/>
        <variable initial_value="1e-16" name="q_GDP" public_interface="out" units="fmol"/>
        <!-- Bond variables-->
        <variable name="vact1_Gi" units="fmol_per_sec"/>
        <variable name="vact2_Gi" units="fmol_per_sec"/>
        <variable name="vhyd_Gi" units="fmol_per_sec"/>
        <variable name="vreassoc_Gi" units="fmol_per_sec"/>
        <variable name="mu_R_M2" units="J_per_mol"/>
        <variable name="mu_Gi" units="J_per_mol"/>
        <variable name="mu_R_M2Gi" units="J_per_mol"/>
        <variable name="mu_LR_M2" units="J_per_mol"/>
        <variable name="mu_LR_M2Gi" units="J_per_mol"/>
        <variable name="mu_aGi_GTP" units="J_per_mol"/>
        <variable name="mu_beta_gamma_Gi" units="J_per_mol"/>
        <variable name="mu_aGi_GDP" units="J_per_mol"/>
        <variable name="mu_Pi" units="J_per_mol"/>
        <variable name="mu_GTP" units="J_per_mol"/>
        <variable name="mu_GDP" units="J_per_mol"/>
        <!-- Constitutive equations-->
        <math xmlns="http://www.w3.org/1998/Math/MathML">
            <apply>
                <eq/>
                <ci>mu_R_M2</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_R_M2</ci>
                            <ci>q_R_M2_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_Gi</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_Gi</ci>
                            <ci>q_Gi_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_R_M2Gi</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_R_M2Gi</ci>
                            <ci>q_R_M2Gi_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_LR_M2</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_LR_M2</ci>
                            <ci>q_LR_M2_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_LR_M2Gi</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_LR_M2Gi</ci>
                            <ci>q_LR_M2Gi_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_aGi_GTP</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_aGi_GTP</ci>
                            <ci>q_aGi_GTP_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_beta_gamma_Gi</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_beta_gamma_Gi</ci>
                            <ci>q_beta_gamma_Gi_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_aGi_GDP</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_aGi_GDP</ci>
                            <ci>q_aGi_GDP_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_Pi</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_Pi</ci>
                            <ci>q_Pi_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_GTP</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_GTP</ci>
                            <ci>q_GTP_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>mu_GDP</ci>
                <apply>
                    <times/>
                    <ci>R</ci>
                    <ci>T</ci>
                    <apply>
                        <ln/>
                        <apply>
                            <times/>
                            <ci>K_GDP</ci>
                            <ci>q_GDP_global</ci>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>vact1_Gi</ci>
                <apply>
                    <times/>
                    <ci>kappa_act1_Gi</ci>
                    <apply>
                        <minus/>
                        <apply>
                            <exp/>
                            <apply>
                                <divide/>
                                <apply>
                                    <plus/>
                                    <ci>mu_R_M2Gi</ci>
                                    <ci>mu_GTP</ci>
                                </apply>
                                <apply>
                                    <times/>
                                    <ci>R</ci>
                                    <ci>T</ci>
                                </apply>
                            </apply>
                        </apply>
                        <apply>
                            <exp/>
                            <apply>
                                <divide/>
                                <apply>
                                    <plus/>
                                    <ci>mu_aGi_GTP</ci>
                                    <ci>mu_beta_gamma_Gi</ci>
                                    <ci>mu_R_M2</ci>
                                    <ci>mu_GDP</ci>
                                </apply>
                                <apply>
                                    <times/>
                                    <ci>R</ci>
                                    <ci>T</ci>
                                </apply>
                            </apply>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>vact2_Gi</ci>
                <apply>
                    <times/>
                    <ci>kappa_act2_Gi</ci>
                    <apply>
                        <minus/>
                        <apply>
                            <exp/>
                            <apply>
                                <divide/>
                                <apply>
                                    <plus/>
                                    <ci>mu_LR_M2Gi</ci>
                                    <ci>mu_GTP</ci>
                                </apply>
                                <apply>
                                    <times/>
                                    <ci>R</ci>
                                    <ci>T</ci>
                                </apply>
                            </apply>
                        </apply>
                        <apply>
                            <exp/>
                            <apply>
                                <divide/>
                                <apply>
                                    <plus/>
                                    <ci>mu_aGi_GTP</ci>
                                    <ci>mu_beta_gamma_Gi</ci>
                                    <ci>mu_LR_M2</ci>
                                    <ci>mu_GDP</ci>
                                </apply>
                                <apply>
                                    <times/>
                                    <ci>R</ci>
                                    <ci>T</ci>
                                </apply>
                            </apply>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>vhyd_Gi</ci>
                <apply>
                    <times/>
                    <ci>kappa_hyd_Gi</ci>
                    <apply>
                        <minus/>
                        <apply>
                            <exp/>
                            <apply>
                                <divide/>
                                <ci>mu_aGi_GTP</ci>
                                <apply>
                                    <times/>
                                    <ci>R</ci>
                                    <ci>T</ci>
                                </apply>
                            </apply>
                        </apply>
                        <apply>
                            <exp/>
                            <apply>
                                <divide/>
                                <apply>
                                    <plus/>
                                    <ci>mu_aGi_GDP</ci>
                                    <ci>mu_Pi</ci>
                                </apply>
                                <apply>
                                    <times/>
                                    <ci>R</ci>
                                    <ci>T</ci>
                                </apply>
                            </apply>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>vreassoc_Gi</ci>
                <apply>
                    <times/>
                    <ci>kappa_reassoc_Gi</ci>
                    <apply>
                        <minus/>
                        <apply>
                            <exp/>
                            <apply>
                                <divide/>
                                <apply>
                                    <plus/>
                                    <ci>mu_aGi_GDP</ci>
                                    <ci>mu_beta_gamma_Gi</ci>
                                </apply>
                                <apply>
                                    <times/>
                                    <ci>R</ci>
                                    <ci>T</ci>
                                </apply>
                            </apply>
                        </apply>
                        <apply>
                            <exp/>
                            <apply>
                                <divide/>
                                <ci>mu_Gi</ci>
                                <apply>
                                    <times/>
                                    <ci>R</ci>
                                    <ci>T</ci>
                                </apply>
                            </apply>
                        </apply>
                    </apply>
                </apply>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_R_M2</ci>
                </apply>
                <ci>vact1_Gi</ci>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_R_M2Gi</ci>
                </apply>
                <apply>
                    <minus/>
                    <ci>vact1_Gi</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_Gi</ci>
                </apply>
                <ci>vreassoc_Gi</ci>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_LR_M2</ci>
                </apply>
                <ci>vact2_Gi</ci>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_LR_M2Gi</ci>
                </apply>
                <apply>
                    <minus/>
                    <ci>vact2_Gi</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_aGi_GTP</ci>
                </apply>
                <apply>
                    <minus/>
                    <apply>
                        <plus/>
                        <ci>vact1_Gi</ci>
                        <ci>vact2_Gi</ci>
                    </apply>
                    <ci>vhyd_Gi</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_beta_gamma_Gi</ci>
                </apply>
                <apply>
                    <minus/>
                    <apply>
                        <plus/>
                        <ci>vact1_Gi</ci>
                        <ci>vact2_Gi</ci>
                    </apply>
                    <ci>vreassoc_Gi</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_aGi_GDP</ci>
                </apply>
                <apply>
                    <minus/>
                    <ci>vhyd_Gi</ci>
                    <ci>vreassoc_Gi</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <apply>
                    <diff/>
                    <bvar>
                        <ci>time</ci>
                    </bvar>
                    <ci>q_Pi</ci>
                </apply>
                <ci>vhyd_Gi</ci>
            </apply>
        </math>
        <!-- mass conservation checks -->
        <variable name="R_T" public_interface="out" units="fmol"/>
        <variable name="Gi_T" public_interface="out" units="fmol"/>
        <math xmlns="http://www.w3.org/1998/Math/MathML">
            <apply>
                <eq/>
                <ci>R_T</ci>
                <apply>
                    <plus/>
                    <ci>q_R_M2_global</ci>
                    <ci>q_R_M2Gi_global</ci>
                    <ci>q_LR_M2_global</ci>
                    <ci>q_LR_M2Gi_global</ci>
                </apply>
            </apply>
            <apply>
                <eq/>
                <ci>Gi_T</ci>
                <apply>
                    <plus/>
                    <ci>q_Gi_global</ci>
                    <ci>q_R_M2Gi_global</ci>
                    <ci>q_LR_M2Gi_global</ci>
                    <ci>q_aGi_GTP_global</ci>
                    <ci>q_aGi_GDP_global</ci>
                </apply>
            </apply>
        </math>
    </component>
    <connection>
        <map_components component_1="environment" component_2="GiProtein"/>
        <map_variables variable_1="time" variable_2="time"/>
        <map_variables variable_1="q_R_M2_mGiProtein" variable_2="q_R_M2"/>
        <map_variables variable_1="q_R_M2" variable_2="q_R_M2_global"/>
        <map_variables variable_1="q_Gi_mGiProtein" variable_2="q_Gi"/>
        <map_variables variable_1="q_Gi" variable_2="q_Gi_global"/>
        <map_variables variable_1="q_R_M2Gi_mGiProtein" variable_2="q_R_M2Gi"/>
        <map_variables variable_1="q_R_M2Gi" variable_2="q_R_M2Gi_global"/>
        <map_variables variable_1="q_LR_M2_mGiProtein" variable_2="q_LR_M2"/>
        <map_variables variable_1="q_LR_M2" variable_2="q_LR_M2_global"/>
        <map_variables variable_1="q_LR_M2Gi_mGiProtein" variable_2="q_LR_M2Gi"/>
        <map_variables variable_1="q_LR_M2Gi" variable_2="q_LR_M2Gi_global"/>
        <map_variables variable_1="q_aGi_GTP_mGiProtein" variable_2="q_aGi_GTP"/>
        <map_variables variable_1="q_aGi_GTP" variable_2="q_aGi_GTP_global"/>
        <map_variables variable_1="q_beta_gamma_Gi_mGiProtein" variable_2="q_beta_gamma_Gi"/>
        <map_variables variable_1="q_beta_gamma_Gi" variable_2="q_beta_gamma_Gi_global"/>
        <map_variables variable_1="q_aGi_GDP_mGiProtein" variable_2="q_aGi_GDP"/>
        <map_variables variable_1="q_aGi_GDP" variable_2="q_aGi_GDP_global"/>
        <map_variables variable_1="q_Pi_mGiProtein" variable_2="q_Pi"/>
        <map_variables variable_1="q_Pi" variable_2="q_Pi_global"/>
        <map_variables variable_1="q_GTP_mGiProtein" variable_2="q_GTP"/>
        <map_variables variable_1="q_GTP" variable_2="q_GTP_global"/>
        <map_variables variable_1="q_GDP_mGiProtein" variable_2="q_GDP"/>
        <map_variables variable_1="q_GDP" variable_2="q_GDP_global"/>
        <map_variables variable_1="R_T" variable_2="R_T"/>
        <map_variables variable_1="Gi_T" variable_2="Gi_T"/>
    </connection>
    <connection>
        <map_components component_1="GiProtein_parameters" component_2="GiProtein"/>
        <map_variables variable_1="kappa_act1_Gi" variable_2="kappa_act1_Gi"/>
        <map_variables variable_1="kappa_act1_Gi" variable_2="kappa_act1_Gi"/>
        <map_variables variable_1="kappa_act1_Gi" variable_2="kappa_act1_Gi"/>
        <map_variables variable_1="kappa_act2_Gi" variable_2="kappa_act2_Gi"/>
        <map_variables variable_1="kappa_hyd_Gi" variable_2="kappa_hyd_Gi"/>
        <map_variables variable_1="kappa_reassoc_Gi" variable_2="kappa_reassoc_Gi"/>
        <map_variables variable_1="K_R_M2" variable_2="K_R_M2"/>
        <map_variables variable_1="K_Gi" variable_2="K_Gi"/>
        <map_variables variable_1="K_R_M2Gi" variable_2="K_R_M2Gi"/>
        <map_variables variable_1="K_LR_M2" variable_2="K_LR_M2"/>
        <map_variables variable_1="K_LR_M2Gi" variable_2="K_LR_M2Gi"/>
        <map_variables variable_1="K_aGi_GTP" variable_2="K_aGi_GTP"/>
        <map_variables variable_1="K_beta_gamma_Gi" variable_2="K_beta_gamma_Gi"/>
        <map_variables variable_1="K_aGi_GDP" variable_2="K_aGi_GDP"/>
        <map_variables variable_1="K_Pi" variable_2="K_Pi"/>
        <map_variables variable_1="K_GTP" variable_2="K_GTP"/>
        <map_variables variable_1="K_GDP" variable_2="K_GDP"/>
    </connection>
    <connection>
        <map_components component_1="constants" component_2="GiProtein"/>
        <map_variables variable_1="R" variable_2="R"/>
        <map_variables variable_1="T" variable_2="T"/>
    </connection>
</model>