Linked Life Data

14529279

Source:http://linkedlifedata.com/resource/pubmed/id/14529279

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
2003-10-7
pubmed:abstractText
Porphyromonas gingivalis is a pathogen associated with periodontal disease, and arginine-specific proteases (gingipains-R) from the bacterium are important virulence factors. The specificity of two forms of gingipain-R, HRgpA and RgpB, for substrate positions C-terminal to the cleavage site was analyzed, and notable differences were observed between the enzymes. Molecular modeling of the HRgpA catalytic domain, based on the structure of RgpB, revealed that there are four amino acid substitutions around the active site of HRgpA relative to RgpB that may explain their different specificity. Previously, differences in the ability of these two gingipain-R forms to cleave a number of proteins were attributed to additional adhesins on HRgpA mediating increased interaction with the substrates. Here, purified RgpA(cat), the catalytic domain of HRgpA, which like RgpB also lacks adhesin subunits, was used to show that the differences between HRgpA and RgpB are probably due to the amino acid substitutions at the active site. The kinetics of cleavage of fibrinogen, a typical protein substrate for the gingipain-R enzymes, which is bound by HRgpA but not RgpA(cat) or RgpB, were evaluated, and it was shown that there was no difference in the cleavage of the fibrinogen Aalpha-chain between the different enzyme forms. HRgpA degraded the fibrinogen Bbeta-chain more efficiently, generating distinct cleavage products. This indicates that while the adhesin domain(s) play(s) a minor role in the cleavage of protein substrates, the major effect is still provided by the amino acid substitutions at the active site of rgpA gene products versus those of the rgpB gene.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11693-700
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Characterization of the specificity of arginine-specific gingipains from Porphyromonas gingivalis reveals active site differences between different forms of the enzymes.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't