Molecular dynamics of surfactant protein C (SP-C): From single molecule to heptameric aggregates

¹ University of Puerto Rico
² University of Southern Denmark

^* To whom correspondence should be addressed. E-mail: eramirez{at}uprm.edu.

Submitted on August 25, 2005
Revised on October 13, 2005
Accepted on 28 December 2005

	Abstract

Surfactant protein C (SP-C) is a membrane associated protein essential for normal respiration. It has been found that the -helix form of SP-C can undergo, under certain conditions, a transformation from an -helix to a -strand conformation that closely resembles amyloid fibrils which are possible contributors to the pathogenesis of pulmonary alveolar proteinosis. Molecular dynamics simulations using the NAMD2 package were performed for systems containing from one to seven SP-C molecules in order to study their behavior in water. The results of our simulations show that unfolding of the protein occurs at the amino terminal and despite this unfolding, no transition from to -strand was observed.

Key Words: amyloid fibrils, protein unfolding