help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

Biophysical Journal 52: 241-248 (1987)
© 1987 the Biophysical Society

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jaworsky, M
Right arrow Articles by Mendelsohn, R
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jaworsky, M
Right arrow Articles by Mendelsohn, R

Unusual partitioning behavior of CaATPase in dipalmitoylphosphatidylethanolamine/dielaidoylphosphatidylcholine++ + mixtures.

M Jaworsky and R Mendelsohn

Department of Chemistry, Newark College of Arts and Sciences, Rutgers University, New Jersey 07102.

ABSTRACT

CaATPase from rabbit sarcoplasmic reticulum has been isolated, purified, stripped of its native lipids, and reconstituted into binary lipid mixtures of dielaidoylphosphatidylcholine (DEPC) and dipalmitoylphosphatidylethanolamine (DPPE) or acyl-chain perdeuterated DPPE (DPPE-d62). The partitioning properties of the protein were determined from differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. Acyl-chain perdeuteration allows the separate determination of the order and melting characteristics of each lipid species with FT-IR. The binary lipid mixture has been shown to be phase separated in the gel state (Brauner, J. W., and R. Mendelsohn, 1986, Biochim. Biophys. Acta, 861:16-24). The solid phases present at low temperatures correspond to a pure DEPC phase and a mixed phase of DEPC/DPPE-d62. Insertion of protein at 37 degrees C leads to a domain of relatively protein-free DPPE-d62 and a phase containing both lipids plus CaATPase. We suggest that CaATPase selects a fixed composition (60% DEPC, 40% DPPE-d62) for its immediate environment. The composition of the lipid in the immediate vicinity of protein is largely independent of the initial DEPC/DPPE-d62 ratios in the reconstitution protocol. The relevance of these results to observations of discrete domains in native membranes is discussed.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1987 by the Biophysical Society.