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Synthetic Potential of Staphylococcus Aureus V8-protease: An Approach Toward Semisynthesis of Covalent Analogs of Alpha-Chain of Hemoglobin S

R Seetharam, A S Acharya

J Cell Biochem. 1986;30(1):87-99.

PMID: 3514639

Abstract:

Enzyme-catalyzed reformation of peptide bonds in the noncovalent fragment systems of proteins has been emerging as a convenient procedure for the semisynthesis of covalent analogs of the respective proteins. Limited proteolysis of the alpha-chain of hemoglobin S with Staphylococcus aureus V8-protease converts the chain into a fragment-complementing system by hydrolyzing the peptide bond Glu(30)-Arg(31) of the chain. Therefore, it is conceivable that semisynthesis of covalent analogs of alpha-chain could be achieved if conditions for the V8-protease catalyzed formation of peptide bonds could be established. The synthetic potential of V8-protease has been now investigated by incubating V8-protease-derived fragments of alpha-chain, namely alpha 1-30 and alpha 31-47 with the enzyme at pH 6.0 in the presence of n-propanol as the organic cosolvent. RP high performance liquid chromatography analysis showed that a new chromatographically distinct component is generated on incubation, and this has been identified as alpha 1-47 by amino acid analysis, redigestion with V8-protease (in the absence of n-propanol), and tryptic peptide mapping. Optimal conditions for the synthesis of alpha 1-47 is at pH 6.0, 4 degrees C, and 24 hr of incubation with 25% n-propanol as organic cosolvent. This stereospecific condensation of the fragments proceeded to a high level of about 50% in 24 hr. Further incubation up to 72 hr did not increase the yield of alpha 1-47, suggesting that an equilibration of synthesis and hydrolysis reactions has been attained. The demonstration of the synthetic potential of V8-protease and the fact that alpha 1-30 and alpha 31-141 interact to form a native-like complex, opens up an approach for the semisynthesis of covalent analogs of alpha-chain of hemoglobin S.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP66676435-A Endoproteinase Glu-C from Staphylococcus aureus V8 Endoproteinase Glu-C from Staphylococcus aureus V8 66676-43-5 Price
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