Summary: | 碩士 === 國立清華大學 === 生命科學系 === 91 === Abstract
Since the purification of snake venom metalloproteinases(SVMP : reprolysin), the experimental data have been accumulated. This enzyme is similar to human matrix metalloproteinases (MMP), both need M2+ cation (Ca2+, Zn2+) to be active, this also means that they will be inhibited by EDTA. There are at least 28 kinds of MMP, they can be divided into five groups: collagenases, gelatinases, stromelysins, membrane type and other type. And SVMP can be catalogued into four types according the their nucleotide sequences (N-I ~ N-IV); they can also be grouped into four different types according to the mature protein size (P-I~P-IV), the molecular weight increases with the group number.
The research of SVMP is mostly related the mechanism of coagulation. Take the SVMP of Naja mocambique mocambique as an example, it will cleave GPIb of platelet, making the bonding of GPIb and VWF factor of membrane failed, then the coagulation will be stopped. And SVMP has been found to have other function: it can cleave the linkage between PSGL-1 and myeloid cell, then the P-selectin on the cell surface of leucocyte can not be recognized, and leucocyte can not undergo chemotaxis.
The other kinds of SVMPs to be purified in this thesis are from Naja nigricollis nigricollis and Naja naja atra, but these two SVMP have not been purified yet. Because studies of SVMP of Naja mocambique mocambique are more abundant, hence taking this as the standard for comparison between all these three SVMP, and using synthesized short peptides as the substrates for SVMP to test enzyme activity. After comparing some characteristics between these three SVMPs, we find the active site of these SVMPs might be the same.
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