Homework SourseThe serine protease mechanism has a conserved catalytic tria
The serine protease mechanism has a conserved catalytic triad of Asp-His-Ser. The specificity of the different serine proteases is governed by the specificity pocket
A) when Asp102 is mutated to Asn in chymotryptosin, the resulting enzyme has only 1/10,000 of the wild-type enzyme. Using what you know of the serine protease mechanism, offer an explanation.
B) if you wanted to design a serine protease that would cleave after a glutamate residue, how would you change the specificity pocket? Draw one possibility
The serine protease mechanism has a conserved catalytic triad of Asp-His-Ser. The specificity of the different serine proteases is governed by the specificity pocket
A) when Asp102 is mutated to Asn in chymotryptosin, the resulting enzyme has only 1/10,000 of the wild-type enzyme. Using what you know of the serine protease mechanism, offer an explanation.
B) if you wanted to design a serine protease that would cleave after a glutamate residue, how would you change the specificity pocket? Draw one possibility
A) when Asp102 is mutated to Asn in chymotryptosin, the resulting enzyme has only 1/10,000 of the wild-type enzyme. Using what you know of the serine protease mechanism, offer an explanation.
B) if you wanted to design a serine protease that would cleave after a glutamate residue, how would you change the specificity pocket? Draw one possibility
Solution
A. Asp102 usually functions as a stabiliser of the His during the catalysis. The stabilisation of His happens through the formation of hydrogen bond using the C-terminal COO group, while the Asp being replaced with Asn it loses the COO- group by which it stabilises the His group. Due to which the catalysis slows down compared to wild-type enzyme.
