Summary for peptidase A01.001: pepsin A

Summary Alignment Sequences Sequence features Distribution Structure Literature Human EST Substrates Inhibitors Pharma

 

Names
MEROPS Namepepsin A
Other namespepsin isoenzyme 3b, pepsin A3, pepsinogen A, pepsinogen A3, PGA3 g.p. (Homo sapiens)
Domain architecture
MEROPS Classification
Classification Clan AA >> Subclan (none) >> Family A1 >> Subfamily A >> A01.001
Holotypepepsin A (Homo sapiens), Uniprot accession P0DJD8 (peptidase unit: 63-388), MERNUM MER0000885
History Identifier created: Handbook of Proteolytic Enzymes (1998) Academic Press, London.
Activity
Catalytic typeAspartic
PeplistIncluded in the Peplist with identifier PL00001
NC-IUBMBSubclass 3.4 (Peptidases) >> Sub-subclass 3.4.23 (Aspartic endopeptidases) >> Peptidase 3.4.23.1
EnzymologyBRENDA database
Proteolytic eventsCutDB database (2 cleavages)
PhysiologyContributes to proteolysis in the vertebrate stomach.
Pharmaceutical relevanceElevated blood levels of pepsinogen 1 have been reported to correlate with predisposition to gastric ulcer, but both may result from infection with Helicobacter pylori (Mertz et al., 2000). The effectiveness of pepstatin in preventing the pathogenesis of reflux esophagitis in a rat model led to the conclusion that pepsin plays a major pathogenic role in the development of acid reflux esophagitis (Nagahama et al., 2006). However, it is not clear to MEROPS that rodents express a form of pepsin that is truly comparable to the human one.
Pathways KEGGProtein digestion and absorption
Other databases WIKIPEDIAhttp://en.wikipedia.org/wiki/Pepsin
Cleavage site specificity Explanations of how to interpret the following cleavage site sequence logo and specificity matrix can be found here.
Cleavage pattern-/-/-/-Scissile bond-/-/-/- (based on 417 cleavages)
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Specificity matrix
 
Amino acid P4 P3 P2 P1 P1' P2' P3' P4'
Gly 39 47 37 19 16 20 20 26
Pro 61 13 8 7 8 5 8 15
Ala 30 51 28 37 45 49 28 35
Val 21 31 26 13 40 37 26 21
Leu 25 28 33 66 51 28 75 30
Ile 17 28 33 13 33 21 23 16
Met 8 12 11 19 10 4 5 6
Phe 15 11 10 86 30 10 17 12
Tyr 13 7 9 16 23 14 17 8
Trp 3 5 5 7 7 3 5 3
Ser 11 28 25 8 13 20 28 26
Thr 29 40 37 18 26 35 22 26
Cys 1 1 3 0 1 1 3 3
Asn 18 12 20 16 15 18 12 19
Gln 18 13 15 12 14 17 23 18
Asp 18 19 23 18 27 16 21 20
Glu 25 29 46 32 17 28 22 27
Lys 32 19 23 17 24 30 27 32
Arg 9 9 10 8 8 50 11 12
His 11 4 8 3 4 4 11 9
Human genetics
Gene symbol Locus Megabases Ensembl Entrez gene Gene Cards OMIM
PGA3 11q13 ENSG00000180860 5220 PGA3 169710