Biodegradability of synthetic branched polypeptide with poly(L-lysine) backbone.
A detailed investigation is reported about the biodegradation of poly[Lys(DL-Alam)], m approximately 3, (AK) the common inside area of a branched polypeptide model system developed by our group over the last decade. Enzymatic hydrolysis was carried out by the exopeptidase aminopeptidase M, or the endopeptidase trypsin, or their mixture. Ion-exchange column chromatography, paper electrophoresis and thin-layer chromatography were utilised to achieve separation of metabolites. Breakdown products were identified by the aid of synthetic oligopeptides representing the potential fragments (DL-Ala2, DL-Ala3, Lys(DL-Alam), m = 1-3). The kinetics and the degree of enzymatic degradation were determined. The ratio of peptide/amino acid amounts in the hydrolysate was found to be 1.07 after 24 h treatment with aminopeptidase M, 3.0 with trypsin and 1.3 with aminopeptidase - trypsin mixture. The overall results indicated that the proteolysis of AK by an aminopeptidase M and trypsin mixture proceeds stepwise at multiple sites on the polypeptide chain. The degradation is significantly retarded as compared to that of alpha- or epsilon-polylysine. A mechanism of degradation is suggested based on the experimental results.
Hudecz
F
F
Eötvös Loránd Tudományegyetem, Szerves Kémiai Tanszék, Budapest.
Kutassi-Kovács
S
S
Mezö
G
G
Szekerke
M
M
D000409:Alanine / Q000031:analogs & derivatives* / Q000378:metabolism; D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018826:CD13 Antigens; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D004151:Dipeptides / Q000378:metabolism*; D004590:Electrophoresis, Paper; D007700:Kinetics; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism; D011107:Polylysine / Q000378:metabolism* / Q000031:analogs & derivatives; D014357:Trypsin / Q000378:metabolism*
D004151:Dipeptides; D009842:Oligopeptides; D010446:Peptide Fragments; C062592:poly(lysine(alanine)); C062593:poly(lysine(alanylalanine)); C062594:poly(lysine(alanyl-alanyl-alanine)); D011107:Polylysine; D000626:Aminopeptidases; D018826:CD13 Antigens; D014357:Trypsin; D000409:Alanine