Mathematical Modelling of the Myosin Light Chain Kinase Activation

Marko Jagodič1, Aleš Fajmut1, Milan Brumen1,2,3

1University of Maribor, PEF, Department of Physics, Maribor, Slovenia, 2 University of Maribor, Medical Faculty, Maribor, Slovenia, 3 Institute Josef Stefan, Ljubljana, Slovenia

The activation of myosin light chain kinase (MLCK) is an important link in the process of smooth muscle contraction. We are introducing a mathematical model of this link describing interactions among calcium (Ca2+), MLCK and calmodulin (CaM). The model consists of a complex binding scheme including 12 reactions and 2 mass conservation relations. Observing the system in the steady state condition we have derived a set of 9 non-linear ordinary equations. Solving it yields the activity of MLCK as a function of cytosolic Ca2+ concentration whereby the MLCK activity is defined to be proportional to 4Ca2+∙MLCK∙CaM complex concentration. Out of various values of the rate constants published in different articles we have taken those which correspond with the Wegscheider condition. Moreover, their influence on the steady state MLCK activity has been studied with the control theory. The agreement with other models as well as experimental results confirm the relevance of our model.

Email: ales.fajmut@uni-mb.si

Address: University of Maribor, Faculty of Education, Koroška c. 160, SI-2000 Maribor