RGD-containing trypsin with both platelet aggregation inhibitory activity and proteolytic activity.
Arg-Gly-Asp (RGD) motif mediates cell adhesion as a major determinant in interactions of disintegrins with cell surface receptors. In order to obtain a mutant trypsin with both high affinity to integrins and retained proteolytic activity, RGDS and RGD were inserted into a rigid turn region and a flexible loop of trypsin, respectively. Wild type trypsin and substituted mutant trypsins, 37RGDS and 77RGD, were expressed in E. coli and purified. Kinetic properties, autolytic stability as well as platelet aggregation inhibitory activity of both 37RGDS and 77RGD were determined. 37RGDS and 77RGD give retained proteolytic activities of 34% and 87%, respectively, and both become less stable to autolysis. 37RGDS shows an obvious inhibition rate of 29% for platelet aggregation and 77RGD gives a rather weak rate of 14% at the same protein concentration of 3.5 microM, while the wild type trypsin shows no inhibitory activity.
National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing, P.R.China.
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Nie
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Tang
D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D009154:Mutation; D009842:Oligopeptides / Q000235:genetics* / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D015202:Protein Engineering; D014357:Trypsin / Q000235:genetics* / Q000494:pharmacology*
D009842:Oligopeptides; D010975:Platelet Aggregation Inhibitors; C047981:arginyl-glycyl-aspartic acid; D014357:Trypsin