Linked Life Data

7574723

Source:http://linkedlifedata.com/resource/pubmed/id/7574723

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-11-6
pubmed:abstractText
The biochemical interactions between digestive proteinases of the Coleoptera pest black vine weevil (Otiorynchus sulcatus) and two plant cysteine proteinase inhibitors, oryzacystatin I (OCI) and oryzacystatin II (OCII), were assessed using gelatin-polyacrylamide gel electrophoresis, OCI-affinity chromatography, and recombinant forms of the two plant inhibitors. The insect proteinases were resolved in gelatin-containing polyacrylamide gels as five major bands, only three of them being totally or partially inactivated by OCI and OCII. The maximal inhibitory effect of both OCs at pH 5.0 was estimated at 40% and the inhibition was stable with time despite the presence of OC-insensitive proteases, indicating the stability of the OCI and OCII effects. After removing OC-sensitive proteinases from the insect crude extract by OCI-affinity chromatography, the effects of the insect cystatin-insensitive proteases on the structural integrity of the free OCs were analyzed. While OCI remained stable, OCII was subjected to limited proteolysis leading to its gradual transformation into a approximately 10.5-kDa unstable intermediate, OCIIi. As shown by the degradation pattern of a glutathione S-transferase (GST)/OCII fusion protein, the appearance of OCIIi resulted from the C-terminal truncation of OCII. Either free or linked to GST, OCIIi was as active against papain and human cathepsin H as OCII, and the initial specificities of the inhibitor for these two cysteine proteinases were conserved after cleavage. Although these observations indicate the high conformational stability of OCII near its active (inhibitory) site, they also suggest a general conformational destabilization of this inhibitor following its initial cleavage, subsequently leading to its complete hydrolysis. This apparent susceptibility of OCII to proteolytic cleavage by the insect proteinases could have major implications when planning the use of this plant cystatin for insect pest control.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
322
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
469-74
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Carboxy-terminal truncation of oryzacystatin II by oryzacystatin-insensitive insect digestive proteinases.
pubmed:affiliation
Pacific Agriculture Research Centre, Agriculture and Agri-Food Canada, British Columbia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't