Reconstituted phosphatidylserine synthase from Escherichia coli is activated by anionic phospholipids and micelle-forming amphiphiles

被引:21
作者
Rilfors, L [1 ]
Niemi, A
Haraldsson, S
Edwards, K
Andersson, AS
Dowhan, W
机构
[1] Umea Univ, Dept Chem Biophys Chem, SE-90187 Umea, Sweden
[2] Uppsala Univ, Dept Chem Phys, SE-75121 Uppsala, Sweden
[3] Univ Texas, Dept Biochem & Mol Biol, Sch Med, Houston, TX 77225 USA
来源
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS | 1999年 / 1438卷 / 02期
关键词
phosphatidylserine synthase; enzyme activity; phospholipid; detergent; cryotransmission electron microscopy; Escherichia coli;
D O I
10.1016/S1388-1981(99)00060-8
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The activity of phosphatidylserine (PS) synthase (CDP-1,2-diacyl-sn-glycerol:L-serine O-phosphatidyltransferase, EC 2.7.8.8) from Escherichia coli was studied after reconstitution with lipid vesicles of various compositions. PS synthase exhibited practically no activity in the absence of a detergent and with the substrate CDP-diacylglycerol (CDP-DAG) present only in the lipid vesicles. Inclusion of octylglucoside (OG) in the assay mixture increased the activity 20- to 1000-fold, the degree of activation depending on the lipid composition of the vesicles. Inclusion of additional CDP-DAG in the assay mixture increased the activity 5- to 25-fold. When the fraction of phosphatidylglycerol (PG) was increased from 15 to 100 mol% in the vesicles the activity increased 10-fold using the assay mixture containing OG. The highest activities were exhibited with the anionic lipids synthesized by E. coli, namely pc, diphosphatidylglycerol (DPG), and phosphatidic acid, while phosphatidylinositol gave a lower activity. Cryotransmission electron microscopy showed that transformation of the vesicles to micelles brings about an activation of the enzyme that is proportional to the degree of micellization. Thus, the activity of PS synthase is modulated by the lipid aggregate structure and by the fraction and type of anionic phospholipid in the aggregates. The increase in the activity caused by PG and DPG is physiologically relevant; it may be part of a regulatory mechanism that keeps the balance between phosphatidylethanolamine, and the sum of PG and DPG, nearly constant in wildtype E. coli cells. (C) 1999 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:281 / 294
页数:14
相关论文
共 52 条
[1]   New aspects on membrane lipid regulation in Acholeplasma laidlawii A and phase equilibria of monoacyldiglucosyldiacylglycerol [J].
Andersson, AS ;
Rilfors, L ;
Bergqvist, M ;
Persson, S ;
Lindblom, G .
BIOCHEMISTRY, 1996, 35 (34) :11119-11130
[2]   Lipid regulation of CTP:phosphocholine cytidylytransferase: Electrostatic, hydrophobic, and synergistic interactions of anionic phospholipids and diacylglycerol [J].
Arnold, RS ;
Cornell, RB .
BIOCHEMISTRY, 1996, 35 (30) :9917-9924
[3]   CONTROLLED ENVIRONMENT VITRIFICATION SYSTEM - AN IMPROVED SAMPLE PREPARATION TECHNIQUE [J].
BELLARE, JR ;
DAVIS, HT ;
SCRIVEN, LE ;
TALMON, Y .
JOURNAL OF ELECTRON MICROSCOPY TECHNIQUE, 1988, 10 (01) :87-111
[4]   Phospholipid-assisted protein folding: phosphatidylethanolamine is required at a late step of the conformational maturation of the polytopic membrane protein lactose permease [J].
Bogdanov, M ;
Dowhan, W .
EMBO JOURNAL, 1998, 17 (18) :5255-5264
[5]   LIPID BILAYER HETEROGENEITIES AND MODULATION OF PHOSPHOLIPASE A(2) ACTIVITY [J].
BURACK, WR ;
BILTONEN, RL .
CHEMISTRY AND PHYSICS OF LIPIDS, 1994, 73 (1-2) :209-222
[7]   Direct imaging by cryo-TEM shows membrane break-up by phospholipase A2 enzymatic activity [J].
Callisen, TH ;
Talmon, Y .
BIOCHEMISTRY, 1998, 37 (31) :10987-10993
[8]  
CARMAN GM, 1979, J BIOL CHEM, V254, P8391
[9]  
CARMAN GM, 1992, METHOD ENZYMOL, V209, P305
[10]   LIPID SIGNALING ENZYMES AND SURFACE DILUTION KINETICS [J].
CARMAN, GM ;
DEEMS, RA ;
DENNIS, EA .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1995, 270 (32) :18711-18714