# BioSysBio:abstracts/2007/Christian Knuepfer/Model explanation

Both models describe the formation and activation of the maturation promoting factor (MPF), a hetero dimer made of the two proteins cyclin and cdc2. Model 1 consists of a set of ordinary differential equations (ODEs) where each equation models the temporal evolution of the concentrations of one of the involved substances wrt. the concentrations of the other substances. Involved substances are: cdc2 ([math]C2[/math]), phosphorylated cdc2 ([math]CP[/math]), inactive MPF ([math]pM[/math]), active MPF ([math]M[/math]), cyclin ([math]Y[/math]), phosphorylated cyclin ([math]YP[/math]), total cdc2 ([math]CT[/math]), adenosine triphosphate ([math]\sim P[/math]), and amino acids (aa). Model 2 is a mathematical abstraction of Model 1 under certain additional biological assumptions. The [math]k_i[/math] are kinetic rate coefficients.

For more details see Tyson, J.: Modeling the cell division cycle: cdc2 and cyclin interactions. Proc Natl Acad Sci USA 88(16) (1991), pp.7328-7332