Document Detail

Purification and characterization of l,(l/d)-aminopeptidase from Guinea pig serum.
MedLine Citation:
PMID:  16513561     Owner:  NLM     Status:  MEDLINE    
Mammalian sera contain enzymes that catalyze the hydrolytic degradation of peptidoglycans and molecules of related structure and are relevant for the metabolism of peptidoglycans. We now report on a novel L,(L/D)-aminopeptidase found in human and mammalian sera. The enzyme hydrolyses the pentapeptide L-Ala-D-iso-Gln-meso-DAP(omegaNH(2))-D-Ala-D-Ala yielding the free L-alanine and the respective tetrapeptide (K(M) 18 mM). L,(L/D)-aminopeptidase from guinea pig serum was highly purified in four chromatographic steps, up to 700-fold. Molecular weight of the enzyme was estimated by HPLC to be approximately 175,000. The configuration of alanine obtained by hydrolysis of the pentapeptide was determined by oxidation with L-amino acid oxidase. The amino acids sequence in the respective tetrapeptide was deduced from the results of mass spectrometry. The novel L,(L/D)-aminopeptidase also hydrolyzed alanine-4-nitroanilide (K(M)=0.6 mM) and several peptides comprising L-amino acids. Peptides containing D-amino acid at the amino end and L-Asp-L-Asp were not the substrates for this enzyme. The purified enzyme also exhibited enkephalin degrading activity, hydrolyzing enkephalins comprising L,L- and L,D-peptide bonds. The enzyme was inhibited strongly by metal chelating agents, bestatin and amastatin.
Marina Krstanović; Marija Brgles; Beata Halassy; Ruza Frkanec; Anto Vrdoljak; Karmen Branović; Jelka Tomasić; Fabio Benedetti
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Preparative biochemistry & biotechnology     Volume:  36     ISSN:  1082-6068     ISO Abbreviation:  Prep. Biochem. Biotechnol.     Publication Date:  2006  
Date Detail:
Created Date:  2006-03-03     Completed Date:  2006-04-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9607037     Medline TA:  Prep Biochem Biotechnol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  175-95     Citation Subset:  IM    
Institute of Immunology Inc., Zagreb, Croatia.
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MeSH Terms
Alanine / chemistry
Amino Acid Sequence
Aminopeptidases / blood*,  chemistry,  isolation & purification*
Guinea Pigs / blood*
Hydrogen-Ion Concentration
Molecular Weight
Oligopeptides / chemistry
Peptidoglycan / chemistry*,  metabolism
Protease Inhibitors / pharmacology
Substrate Specificity
Reg. No./Substance:
0/Oligopeptides; 0/Peptidoglycan; 0/Protease Inhibitors; 56-41-7/Alanine; EC 3.4.11.-/Aminopeptidases

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