Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two aminopeptidases which hydrolyze Metenkephalin at the Tyr-Gly bond have been solubilized from rat brain membranes and resolved by ion-exchange chromatography. These aminopeptidase are designated MI and MII based on the order in which they are eluted during ion-exchange chromatography. The two aminopeptidases can be distinguished kinetically; aminopeptidase MI hydrolyzes L-arginine beta-naphthylamide 17 times faster than L-alanine beta-naphythylamide, while only a 1.7-fold difference is exhibited by aminopeptidase MII. Aminopeptidase MII exhibits a higher affinity for amino acid beta-naphthylamides, Met-enkephalin, Leu-enkephalin, and the inhibitor puromycin as compared to aminopeptidase MI. Greater than 90% of aminopeptidase MII activity is lost upon dialysis against ethylene-diaminetetraacetate (EDTA) but can be reconstituted with CoCl2 and MnCl2. In contrast, aminopeptidase MI loses only 30% of its activity when dialyzed against EDTA. In addition to cleaving the Tyr-Gly bond of Met-enkephalin, aminopeptidase MII also cleaves the Tyr-Gly bond of alpha- and gamma-endorphin. Hydrolysis of Met-enkephalin by intact membranes derived from whole rat brain occurs primarily by cleavage at the Tyr-Gly bond, with this activity attributable to aminopeptidase MII.
 ...
PMID:Solubilization and characterization of two rat brain membrane-bound aminopeptidases active on Met-enkephalin. 723 6

The proteolytic system of Bifidobacterium animalis subsp. lactis was analyzed, and an intracellular endopeptidase (PepO) was identified and characterized. This work reports the first complete cloning, purification, and characterization of a proteolytic enzyme in Bifidobacterium spp. Aminopeptidase activities (general aminopeptidases, proline iminopeptidase, X-prolyl dipeptidylaminopeptidase) found in cell extracts of B. animalis subsp. lactis were higher for cells that had been grown in a milk-based medium than for those grown in MRS. A high specific proline iminopeptidase activity was observed in B. animalis subsp. lactis. Whole cells and cell wall-bound protein fractions showed no caseinolytic activity; however, the combined action of intracellular proteolytic enzymes could hydrolyze casein fractions rapidly. The endopeptidase activity of B. animalis subsp. lactis was examined in more detail, and the gene encoding an endopeptidase O in B. animalis subsp. lactis was cloned and overexpressed in Escherichia coli. The deduced amino acid sequence for B. animalis subsp. lactis PepO indicated that it is a member of the M13 peptidase family of zinc metallopeptidases and displays 67.4% sequence homology with the predicted PepO protein from Bifidobacterium longum. The recombinant enzyme was shown to be a 74-kDa monomer. Activity of B. animalis subsp. lactis PepO was found with oligopeptide substrates of at least 5 amino acid residues, such as met-enkephalin, and with larger substrates, such as the 23-amino-acid peptide alpha s1-casein(f1-23). The predominant peptide bond cleaved by B. animalis subsp. lactis PepO was on the N-terminal side of phenylalanine residues. The enzyme also showed a post-proline secondary cleavage site.
 ...
PMID:Enzymatic ability of Bifidobacterium animalis subsp. lactis to hydrolyze milk proteins: identification and characterization of endopeptidase O. 1633 35