52357-40-1

Upstream product

• 16012-70-7 benzyloxycarbonyl-L-alanyl-L-alanine 
• 1668-13-9 L-alanine-p-nitroanilide 
• 2483-52-5 benzyl ((S)-1-(((S)-1-hydrazinyl-1-oxopropan-2-yl)amino)-1-oxopropan-2-yl)carbamate 

Downstream Products

• 52299-14-6 N-succinyl-L-alanyl-L-alanyl-L-alanine 4-nitroanilide 
• 60354-61-2 L-Ala-L-Ala-L-Ala-pNA 

Relevant academic research and scientific papers

Biocatalytic properties of thermolysin immobilized on polyvinyl alcohol cryogel

Preparations with different contents of thermolysin were obtained by the immobilization of the enzyme on granulated polyvinyl alcohol cryogel. Their activity and stability in an aqueous medium and in mixtures of polar organic solvents of different composition were investigated. The catalytic properties of the preparations in reactions of peptide bond formation were studied, and the optimal amount of the biocatalyst, the concentrations of initial reagents, and the ratios of organic solvents and water necessary for effective enzymatic peptide synthesis catalyzed by immobilized thermolysin were determined. A series of peptides of the general formula Z-Ala-Ala-Xaa-pNA, where Xaa = Leu, Ile, Phe, Val, or Ala, were synthesized, and the immobilized enzyme was shown to retain substrate specificity in an organic medium.

ROLE OF AMINO ACID RESIDUES IN CHROMOGENIC SUBSTRATES CLEAVED BY PANCREATIC ELASTASE

Anionic chromogenic substrates, 3-carboxypropionyl tripeptide p-nitroanilides modified with glycine, β-alanine, alanine, leucine, and proline in positions P1, P2, and P3 were synthesized.The substrates were digested with pancreatic elastase and the values of Km, kcat, and kcat/Km were determined.Alanine plays a decisive role in position P1, substrates with glycine or β-alanine in this position are not cleaved.The substitution in P2 is dominant for proline; next follow alanine, leucine, and glycine.The substitution in P3 is the least specific one.

p-Nitroanilides of 3-carboxypropionyl-peptides. Their cleavage by elastase, trypsin, and chymotrypsin.

Fourteen 3-carboxypropionyl-tripeptide-p-nitroanilides of the general formula 3-carboxypropionyl-alanyl-alanyl-Y-p-nitroanilide (Y = glycine, norvaline, S-methylcysteine, valine, norleucine, S-ethylcysteine, methionine, leucine, isoleucine, phenylalanine, tyrosine, S-benzylcysteine, Calpha-phenylglycine, and proline) were synthesized and their cleavage by elastase, trypsin, and chymotrypsin (Km, kcat and kcat/Km) was determined. The significance of amino acid residues in the position of Y was evaluated firstly with respect to their structure (topographically), and secondly with respect to their free energy (thermodynamically). The alanine residue substrate was cleaved best by elastase, the phenylalanine substrate by chymotrypsin. Trypsin cleaved two substrates only, that is those containing a phenylalanine and a tyrosine residue. The optimum length of the elastolytic substrates was studied in a series of N-3-carboxypropionyl-(Ala)n-p-nitroanilides (n = 1, 2, 3, 4, 5), N-3-carboxypropionyl-(Gly)n-p-nitroanilides (n = 1, 2, 3), and in p-nitroanilides of fatty acids with two to seven carbon atoms. Elastase cleaved tri, tetra, and pentapeptides of alanine. p-Nitroanilides of the glycine series, as well as p-nitroanilides of fatty acids were not cleaved. 3-Carboxypropionyl-tetra-alanine-p-nitroanilide was the most suitable substrate so far found for elastase cleavage; it is not cleaved by trypsin nor chymotrypsin. The optimum distance between Y and the terminal anionic carboxyl residue was found to be 1.8 nm in elastolytic substrates.