[Preparation and characterization of a single chain antibody fragment of mAb SZ-21 against platelets GPIIIa].
OBJECTIVE
To prepare a single chain antibody (ScFv) of mAb SZ-21 against platelet GPIIIa for its future clinical application.


METHODS
The expression vector pET20b-SZ-21ScFv was constructed and the fusion protein was expressed in E. coli BL21 (DE3) PlysS. The activated fusion protein was obtained after a series of purification steps, including cell breakage, inclusion body solubilization, His-bind resin affinity chromatography and protein refolding.


RESULTS
The fusion protein yields were up to 21% of the total amount of bacteria protein. The ScFv fragment could inhibit ADP-induced platelets aggregation in a dose-dependent manner in vitro and the maximal inhibition rate was obtained at a concentration of 20 micro g/ml. It also reacted with endothelial cells as detected by flow cytometry. Moreover, the ScFv fragment was able to inhibit the binding of fibrinogen to platelet.


CONCLUSIONS
The SZ-21ScFv fragment had the activity to inhibit platelets aggregation and the binding of fibrinogen to platelet, being potentially useful for the treatment of thrombotic diseases.
An
Guangyu
G
Jiangsu Institute of Hematology, The First Affiliated Hospital of Suzhou University, Suzhou 215006, China.
Dong
Ningzheng
N
Shao
Bojing
B
Zhu
Mingqing
M
Ruan
Changgeng
C
D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D001792:Blood Platelets / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007128:Immunoglobulin Fragments / Q000494:pharmacology*; D010974:Platelet Aggregation; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000494:pharmacology*
D000911:Antibodies, Monoclonal; D007128:Immunoglobulin Fragments; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011993:Recombinant Fusion Proteins; C055966:immunoglobulin Fv; D005340:Fibrinogen