ISSN:
1573-4943
Keywords:
human angiogenin
;
bovine ribonuclease
;
protein homology
;
limited proteolysis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The primary structure of angiogenin is 33% identical to that of bovine pancreatic ribonuclease (RNase), but the enzymatic activities of the two proteins differ markedly. Similarly, their susceptibilities to limited proteolysis differ as well. In contrast to RNase, angiogenin totally resists proteolysis by subtilisin. Indeed, among 16 proteases examined, only endoprotease Lys-C, trypsin, and pepsin are able to cleave angiogenin. Even with prolonged incubation, endoprotease Lys-C selectively cleaves the Lys-60-Asn-61 bond; the product retains full ribonucleolytic activity. Initially, trypsin also cleaves this same bond, but with time it causes extensive degradation. Pepsin, atpH 2, cleaves the Phe-9-Leu-10 bond, to give angiogenin (10–123), which displays ∼15% of the native activity toward ribosomal RNA (rRNA). The susceptibility to proteolysis and/or the sites of cleavage of angiogenin and bovine RNase differ markedly despite their structural homology. These differences are considered in terms of the amino acid sequences of the two proteins.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01024885
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