102683-28-3

Upstream product

• 65160-70-5 D-arginine methyl ester 
• 13512-31-7 N-(benzyloxycarbonyl)-L-tyrosine methyl ester 
• 22888-59-1 methyl (2R)-2-amino-5-carbamimidamidopentanoate dihydrochloride 
• 111237-99-1 D-Arg-OMe*HCl 
• 501-53-1 benzyl chloroformate 
• 3417-91-2 L-tyrosine methyl ester HCl 
• 157-06-2 D-arginine 
• 102988-95-4 C₂₂H₂₅NO₇ 

Relevant academic research and scientific papers

Kinetically Controlled Peptide Bond Formation in Anhydrous Alcohol Catalyzed by the Industrial Protease Alcalase

The industrial alkaline protease alcalase has been found to be very stable (half life > 5 days in ethanol or 2-methyl-2-propanol) and active in alcoholic solvents (except methanol).Procedures have been developed for alcalase-catalyzed, kinetically controlled peptide bond formation in anhydrous alcohol (ethanol, 2-methyl-2-propanol).Studies of the selectivity of an alcalase-catalyzed reaction show that only L-amino acid acyl donors are substrates at the p-1 subsite of alcalase; at the p-1' subsite both D- and L-amino acid nucleophiles are substrates.Other amino compounds such as benzylamine and phenylhydrazine are good nucleophiles.Studies of the effect of the water content of the reaction solution on the yield in the synthesis of Moz-Phe-Leu-NH2 showed that the 95percent yield obtained in anhydrous 2-methyl-2-propanol was decreased to 48percent in 2-methyl-2-propanol containing 4.86percent water.

Enzymes in organic synthesis: Use of subtilisin and a highly stable mutant derived from multiple site-specific mutations

A subtilisin mutant (subtilisin 8350) derived from subtilisin BPN' via six-specific mutations (Met50Phe, Gly169Ala, Asn76Asp, Gln206Cys, Tyr217Lys, and Asn218Ser) was found to be 100 times more stable than the wild-type enzyme in aqueous solution at room temperature and 50 times more stable than the wild type in anhydrous dimethylformamide. Kinetic studies using ester, thio ester, and amide substrates, and the transition-state analogue inhibitor Boc-Ala-Val-Phe-CF3, indicate the both the wild-type and the mutant enzymes have very similar specificities and catalytic properties. The inhibition constant (K(i)) = 5.0 μM) for the wild-type enzyme is approximately 5 times that of the mutant enzyme (K(i)) = 1.1 μM), suggesting that the mutant enzyme binds the reaction transition state more strongly than the wild-type enzyme. This result is consistent with the observed rate constants for the corresponding ester and amide substrates; i.e. the k(cat)/k(m) values for the mutant are larger than those for hhe wild-type enzyme. Application of the mutant enzyme and the wild-type enzyme to organic synthesis has been demonstrated in the regioselective acylation of nucleosides in anhydrous dimethylformamide (with 65-100% regioselectivity at the 5'-position), in the enantioselective hydrolysis of N-protected and unprotected common and uncommon amino acid esters in water (with 85-98% enantioselectivity for the L-isomer), and in the synthesis of di- and oligopeptides via aminolysis of N-protected amino acid and peptide esters. The enzymatic peptide synthesis was carried out under high concentrations of DMF (~50%) to improve substrate solubility and to minimize enzymatic peptide cleavage. Low enantioselectivity was observed in the enzymatic transformation of non-amino acid alcohols and acids.

A Search for Peptide Ligase: Cosolvent-Mediated Conversion of Proteases to Esterases for Irreversible Synthesis of Peptides

Serine and cysteine proteases (trypsin, chymotrypsin, papain, subtilisin) in the presence of certain concentrations of water-miscible organic solvents express no amidase activities.The esterase activities, however, remain significant.These modified enzyme

Enzyme-Catalyzed Irreversible Formation of Peptides Containing D-Amino Acids

Procedures have been developed for the preparation of dipeptides Z-L-Tyr-D-X and Z-L-Phe-D-X using Z-L-Tyr-OMe (or Z-L-Phe-OMe) and D-amino acid esters or amides (D-X) as substrates and soluble or immobilized α-chymotrypsin as a catalyst.The formation of each of these peptides in miscible or immiscible organic solvent-water systems in a kinetically controlled approach is virtually irreversible with no side reactions or racemization.Kinetic studies indicate that D-amino acid esters are about 100 times that of water and 10percent that of L-amino acid esters as a nucleophile in deacylation reactions.The effects of pH, organic solvents, temperature, and substrate and enzyme concentrations on the yield and the stability of the enzyme in syntheses have been studied and the results compared with those in the enzyme-catalyzed formation of L-L-dipeptides.

Enzyme-catalysed Synthesis of Peptides containing D-Amino Acids

Practical procedures are described for the preparation of D-amino acid-containing dipeptides using α-chymotrypsin and the Met(O)192-modified enzyme as a catalyst.