View Full Document

6 views

Unformatted text preview:

CONFORMATION OF LIQUID N ALKANES F GOODSAID ZALDUONDO AND D M ENGELMAN Department ofMolecular Biophysics and Biochemistry Yale University New Haven Connecticut 06511 ABSTRACr The conformations of liquid n alkanes have been studied using neutron scattering techniques to better understand the conformational forces present in membrane lipid interiors We have studied hydrocarbon chains having lengths comparable to those found for esterified membrane lipid fatty acids and find that the steric constraints of packing in the liquid state do not change the conformational distributions of hydrocarbon chains from those imposed by the intrachain forces present in the gas phase It follows that the central region of membranes containing lipids in the disordered state should contain hydrocarbon chain conformations determined primarily by intrachain forces INTRODUCTION Biological membranes containing lipids in the disordered liquid crystalline state scatter x rays and neutrons in a broad band of intensity centered near 4 6 A 1 2 The scattering from alkanes in the liquid state is very similar in this region 3 and has suggested to some a close similarity of properties with membrane interiors 4 Observations of membrane viscosities support such a contention While it would be desirable to study the relative roles of steric interactions bond rotation potentials and anisotropic origin constraints in natural membranes it has frequently proved useful to explore simpler systems which permit a more precise characterization It is therefore of some interest to explore the properties of liquid alkanes having chain lengths comparable to those of membrane fatty acids to improve our understanding of the conformations present in membrane lipid interiors and the forces giving rise to those conformations In this study we ask whether the steric constraints of packing in the liquid state change the conformational distributions of hydrocarbon chains from those imposed by the intrachain forces present in



Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view CONFORMATION OF LIQUID N-ALKANES and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view CONFORMATION OF LIQUID N-ALKANES and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?