Accession Number : ADA185356

Title :   Elastic Molecular Machines and a New Motive Force in Protein Mechanisms,

Corporate Author : ALABAMA UNIV IN BIRMINGHAM LAB OF MOLECULAR BIOPHYSICS

Personal Author(s) : Urry, Dan W

PDF Url : ADA185356

Report Date : Jan 1987

Pagination or Media Count : 32

Abstract : It is demonstrated that polypentapeptide, (Val1-Pro2-Gly3-Val4-Gly5)n when gamma-irradiation cross-linked, can perform work on raising the temperature from 20 to 40 C. This is due to an inverse temperature transition leading to a regular helical structure called a dynamic beta-spiral which exhibits entropic elastomeric force. Once a synthetic elastomeric matrix is formed from 20% Glu4-polypentapeptide, it should be possible at 50 C to turn on elastomeric force by changing the pH from 7 to 2 and to turn 'off' elastomeric force by returning the pH to 7. This is called mechanochemical coupling of the first kind, and, in addition to ionization and deionization, it should be possible similarly to turn off and on elastomeric force by phosphorylation and dephosphorylation, respectively. When the elastomeric state is arrived at by means of a regular transition from a more ordered state to a less ordered state on raising the temperature and a chemical process can change the temperature of the transition, this is referred to as mechanochemical coupling of the second kind. It is proposed that these new considerations are relevant to mechanisms for the turning on and off of elastic forces in protein mechanisms as varied as those of enzymes and muscle contraction.

Descriptors :   *PEPTIDES, *PROTEINS, *ELASTIC PROPERTIES, MOLECULE MOLECULE INTERACTIONS, HYDROPHOBIC PROPERTIES, PH FACTOR, PHOSPHORYLATION, COVALENT BONDS, TEMPERATURE, ENZYMES, MUSCLES, CONTRACTION

Subject Categories : Biochemistry
      Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE