Citation Context

...purified from tissues or cells for use in a particular assay. For example, the I2020T alters the proportion of protein in an active DYG-in pocket conformation, but the increase in kinase activity can be negated depending on assay conditions and the nature of the kinase substrate.27 Similar active-state stabilization mechanisms may be occurring in the ROC domain for other pathogenic mutations.28 Active-state conformations can also be affected variably by at least seven other known factors, usually present in unknown stoichiometries with respect to enzyme, in published kinase-assay experiments: (1) LRRK2 protein cofactors and interactors such as 14-3-3 and heatshock proteins that coelute with LRRK2, as well as other less-abundant interacting factors such as ArfGap1, (2 and 3) metal such as Mg11 bound to the GTPase domain, and kinase domain, (4) guanine nucleotide bound to the GTPase domain, (5) adenosine nucleotide bound to the kinase domain, (6) peptide substrate docked in the kinase domain, and (7) substrates of autophosphorylation docked to the kinase domain (readily saturable). All seven of these substrates or cofactors can, in a coordinated way, interact to affect LRRK2 kinase outp...