CONFORMATIONAL AND ELECTROSTATIC PROPERTIES OF V-G-G-V-G, A TYPICAL SEQUENCE OF THE GLYCINE-RICH REGIONS OF ELASTIN - AN AB-INITIO QUANTUM MOLECULAR STUDY

The conformational analysis and electrostatic properties of the monome ric sequence V-G-G-V-G of the glycine-rich regions of elastin is prese nted with the aim of explaining NMR and CD experimental results. On th e basis of the molecular model NH3+-V-G-G-V-G-COO-, Gaussian 92 quantu m-molecular computations were performed by using principally an ab ini tio method at the 3-21G level and AM1. The occurrence of local seconda ry structures and of beta I. beta II, beta II' and VIa turns is discus sed. Our results clearly demonstrate that the transconformations beta I-->half turn (which was invoked to explain experimental results) and beta I-->beta II' are theoretically allowed. (C) Munksgaard 1996.