Enzymatic characterization of peptidic materials isolated from aqueous solutions of ammonium cyanide (pH 9) and hydrocyanic acid (pH 6) exposed to ionizing radiation

• Published in: Journal of molecular evolution Vol. 18; no. 2; pp. 130 - 136
• Main Authors: Niketic, V, Draganić, Z, Nesković, S, Draganić, I
• Format: Journal Article
• Language: English
• Published: Germany 01-01-1982
• Subjects: Amino Acids - analysis; Aminopeptidases; CD13 Antigens; Chemical Phenomena; Chemistry; Cobalt Radioisotopes; Cyanides; Hydrogen Cyanide; Molecular Weight; Peptide Fragments - isolation & purification; Peptides - analysis; Peptides - radiation effects; Pronase; Solutions
• ISSN: 0022-2844; 1432-1432
• DOI: 10.1007/BF01810832

The enzymatic digestion of some radiolytically produced peptidic materials was examined. The substrates were compounds isolated from 0.1 molar solutions of NH4CN (pH 9) and HCN (pH 6), after their exposure to gamma rays from a 60Co source (15-20 Mrad doses). Commercial proteolytic enzymes pronase and aminopeptidase M were used. The examined materials were of composite nature and proteolytic action was systematically observed after their subsequent purification. In some fractions the effect was found to be positive with up to 30% of peptide bonds cleaved with respect to the amino acid content. These findings support our previous conclusions on the free radical induced formation of peptidic backbones without the intervention of amino acids. Some side effects were also noted which might be of interest in observations on enzymatic cleavage of other composite peptidic materials of abiotic origin.