Effect of Cation Concentrations and Temperature on the Rates of Aggregation of Acidic Phospholipid Vesicles: Application to Fusion

1980 ◽  
pp. 75-106 ◽  
Author(s):  
SHLOMO NIR ◽  
JOE BENTZ ◽  
ARCHIE R. PORTIS
Keyword(s):  
Phospholipid Vesicles ◽  
Acidic Phospholipid

Kinetics of Beryllium-Induced Aggregation of Acidic Phospholipid Vesicles

1996 ◽  
Vol 178 (2) ◽  
pp. 581-585 ◽  
Author(s):  
Hideyuki Minami ◽  
Tohru Inoue ◽  
Ryosuke Simozawa
Keyword(s):  
Phospholipid Vesicles ◽  
Acidic Phospholipid ◽  
Induced Aggregation ◽  
Kinetics Of

THE EFFECT OF PROCOAGULANT PHOSPHOLIPID VESICLES WITH NET POSITIVE CHARGE ON THE ACTIVITY OF PROTHROMBINASE

1987 ◽  
Author(s):  
J Rosing ◽  
H Speijer ◽  
J W P Govers-Riemslag ◽  
R F A Zwaal
Keyword(s):  
Vitamin K ◽  
Negative Charge ◽  
Positive Charge ◽  
Coagulation Factor ◽  
Phospholipid Vesicles ◽  
Electrostatic Model ◽  
Acidic Phospholipid ◽  
Positively Charged ◽  
Net Positive Charge ◽  
Prothrombin Activation

It is generally thought that procoagulant phospholipid surfaces that promote the activation of vitamin K-dependent coagulation factors should have a net negative charge in order to promote calcium-dependent binding of the enzymes (FVIIa, FIXa and FXa) and substrates (prothrombin and FX) of the coagulation factor-activating complexes. Two models have been proposed to explain calcium-mediated association of vitamin K-dependent proteins with phospholipid: a) an electrostatic model, in which a positively-charged protein-calcium complex is attracted by a negatively-charged phospholipid surface and b) a chelation model in which a coordination complex is formed between calcium ions, γ-carboxyglutamic acids of the proteins and negatively-charged membrane phospholipids. To study the effect of the electrostatic potential of phospholipid vesicles on their activity in the pro-thrombinase complex the net charge of vesicles was varied by introduction of varying amounts of positively-charged stearylamine in the membrane surface. Introduction of 0-15 mole% stearylamine in phospholipid vesicles that contained 5 mole% phosphatidylseri-ne (PS) hardly affected their activity in prothrombin activation. Electrophoretic analysis showed that vesicles with > 5 mole% stearylamine had a net positive charge. The procoagulant activity of vesicles that contained phosphatidic acid, phosphatidylglyce-rol, phosphatidylinositol or phosphatidyl-glactate (PLac) as acidic phospholipid was much more effected by incorporation of stearylamine. Amounts of stearylamine that compensated the negative charge of acidic phospholipid caused considerable inhibition of the activity of the latter vesicles in prothrombin activation. The comparison of vesicles containing PS and PLac as acidic phospholipid is of special interest. PS and PLac only differ by the presence of NH+ 3-group in the serine moiety of PS. Thus, in spite of the fact that vesicles with PLac are more negatively charged than vesicles with PS, they are less procoagulant. Our results show that a) although procoagulant membranes have to contain acidic phospholipids there is no requirement for a net negative charge, b) the amino group of phosphatidylserine has an important function in the interaction of procoagulant membranes with vitamin K-dependent proteins and c) the chelation model can satisfactorily explain calcium-mediated lipid-protein association.

Abnormal aggregation behavior of acidic phospholipid vesicles in the very low concentration range of divalent cations

1992 ◽  
Vol 149 (2) ◽  
pp. 536-541 ◽  
Author(s):  
Mikiji Shigematsu ◽  
Tetsuo Fujie ◽  
Tohru Inoue ◽  
Yoshio Murata ◽  
Mitsuru Tanaka ◽  
...  
Keyword(s):  
Divalent Cations ◽  
Aggregation Behavior ◽  
Phospholipid Vesicles ◽  
Low Concentration ◽  
Acidic Phospholipid

scholarly journals The interaction of bovine factor IX, its activation intermediate, factor IX α, and its activation products, factor IXaα and factor IXaβ, with acidic phospholipid vesicles of various compositions

1986 ◽  
Vol 236 (3) ◽  
pp. 861-869 ◽  
Author(s):  
J M Beals ◽  
F J Castellino
Keyword(s):  
Binding Sites ◽  
Dissociation Constants ◽  
Factor Ix ◽  
Phospholipid Vesicles ◽  
Acidic Phospholipid ◽  
Factor Ixa ◽  
Activation Products ◽  
Alpha Factor ◽  
Number Of Binding Sites ◽  
Bovine Factor

The interactions of bovine factor IX, its activation intermediate, Factor IX alpha, and its activation products, Factor IXa alpha and Factor IXa beta, with phospholipid vesicles, of mean radius of approx. 30 nm, containing various amounts of phosphatidylserine (PS) and phosphatidylcholine (PC), have been examined. For Factor IX, Factor IX alpha, Factor IXa alpha and Factor IXa beta, the dissociation constants, at saturating levels of Ca2+, are independent of the PS concentration in the vesicle after levels of 20-30% (w/w) have been reached, and attain minimum values of approx. 1.7, 1.7, 0.7 and 1.0 microM, respectively, with vesicles containing 50% PS. The amount of protein bound per vesicle particle is independent of the PS content, above 20% PS, for Factor IX and Factor IXa beta, with values of approx. 995-1197 and 1128-1566 molecules/vesicle, respectively. With Factor IX alpha, a dependence on the amount of protein bound with the content of PS is seen, which ranges from 338 to 619 molecules/vesicle with membranes containing 30-50% PS. For Factor IXa alpha, no regularity is noted and a range of 583-1083 molecules of protein/vesicle is observed with the systems employed. Examination of the radii of the proteins on the vesicle demonstrates that Factors IX alpha and IXa alpha occupy considerably more of the surface than do Factors IX and IXa beta, suggesting that a reason for the decreased number of binding sites for the former two proteins on the vesicle may be related to their greater surface spatial requirements.

Interaction of Enantiomers of Lysyl-7-Azatryptophyl-Lysine with Acidic Phospholipid Vesicles: A Fluorescence Study

1995 ◽  
Vol 49 (1) ◽  
pp. 51-59 ◽  
Author(s):  
J. D. Brennan ◽  
I. D. Clark ◽  
C. W. V. Hogue ◽  
A. S. Ito ◽  
L. Juliano ◽  
...  
Keyword(s):  
Phospholipid Vesicles ◽  
Fluorescence Study ◽  
Acidic Phospholipid
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