I will present a modeling approach which allows to describe the friction effect due to transiently remodeling protein linkages. The model has been developed in the context of the modeling of the actin cytoskeleton. A microscopic model is formulated which couples a force balance equation that defines the position of a moving binding site to a renewal model for the age distribution of linkages. The renewal model describes the remodelling process of linkages which attach and break with given probabilities.

In the asymptotic limit of infinitesimally rapid turnover of linkages one derives a macroscopic friction law. The friction law is nonlinear depending on the possible dependence of the off-rate of linkages on their mechancial load and allows to model stick-slip dynamics and the tearing-off of the binding site moving under protein mediated friction.

Apart from the formal derivation of the model I also sketch the mathematical analyis of the model which is based on a specific Lyapunov-functional for the renewal model, a comparison principle which applies to non-convolution linear Volterra kernels and a-priori estimates which control velocity of the moving binding site(s). For the case of linear friction I will present a rigorous result on the convergence of solutions to the limit friction law.