Study on the mechanism of the annexin II-mediated co-assembly of t-PA and plasminogen.
- Author:
Xiaohui ZHANG
1
;
Huarong ZHOU
;
Guanxin SHEN
;
Zhongping LIU
;
Yu HU
;
Wenning WEI
;
Shanjun SONG
Author Information
1. Department of Hematology, Xiehe Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022.
- Publication Type:Journal Article
- MeSH:
Annexin A2;
pharmacology;
Cells, Cultured;
Endothelium, Vascular;
cytology;
metabolism;
Fibrinolysis;
Humans;
Plasminogen;
metabolism;
Recombinant Proteins;
pharmacology;
Tissue Plasminogen Activator;
metabolism;
Umbilical Veins;
cytology
- From:
Journal of Huazhong University of Science and Technology (Medical Sciences)
2002;22(1):21-76
- CountryChina
- Language:English
-
Abstract:
In order to further investigate the effect of annexin II (Ann-II) on tissue plasminogen activator (t-PA)-dependent plasminogen (PLG) activation and its interactive mechanism, recombinant native Ann-II bound t-PA, PLG and plasmin with high affinity was examined. The flow cytometric assay showed that the ann-II expression rate was higher in the human umbilical vein endothelial cell (HUVEC) (87.65%) than in the HL-60 cells as controls (35.79%). Two irrelevant proteins, bovine serum albumin (BSA) and equine IgG (EIG) had no effect on the production of plasmin. Ann-II-mediated enhancement of t-PA-dependent PLG activation was inhibited by epsilon-aminocaproic acid or by pretreatment of Ann-II with carboxypeptidase B with the inhibitive rate being 77.8% and 77.0%, respectively. It was revealed that the effect of Ann-II on PLG activation was specific for t-PA. Urokinase didn't bind to Ann-II, demonstrating the role of receptor-related lysine residues on activation of PLG, showing that the Ann-II-PLG interaction was dependent upon carboxyl-terminal lysine residues. These findings suggest that annexin II-mediated co-assembly of t-PA and PLG may promote plasmin generation and play a key role in modulating fibrinolysis on the endothelial surface.
