Linked Life Data

1787424

Source:http://linkedlifedata.com/resource/pubmed/id/1787424

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1992-3-25
pubmed:abstractText
The proteinase activity present in homogenates of trophozoites of Giardia lamblia, active on azocasein and urea-denaturated hemoglobin, was separated into two different enzymes by a series of purification procedures. These procedures included gel filtration on Fractogel TSK HW-55 (F), organomercurial agarose affinity chromatography, and ion exchange chromatography on DEAE-cellulose. By chromatography on Sephadex G-100, two purified enzymes exhibited relative molecular weights of Mr = 95,000 and 35,000 +/- 10%, respectively. On the basis of inhibition by thiol reagents and abrogation of this effect by dithiothreitol and cysteine, they were identified as cysteine proteinases. Proteinase I (Mr = 95,000) and proteinase II (Mr = 35,000) were active against the beta-chain of insulin releasing characteristic fragments. However, differences in substrate specificities of the two enzymes could be observed by using synthetic peptides that represent sequences 1-6, 8-18, and 20-30 of the insulin beta-chain. Furthermore, the synthetic tetrapeptides Arg-Gly-Phe-Phe, Arg-Gly-Leu-Hyp, and Arg-Arg-Phe-Phe were hydrolyzed by the two proteinases releasing Phe-Phe and Leu-Hyp, respectively. Compared with Arg-Gly-Phe-Phe, the rates of hydrolysis of Arg-Gly-Leu-Hyp and Arg-Arg-Phe-Phe at substrate concentrations of 1 mM were 91% and 63% (proteinase I) and 80% and 57% (proteinase II), respectively.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0022-3921
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
378-83
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:articleTitle
Purification and substrate specificity of two cysteine proteinases of Giardia lamblia.
pubmed:affiliation
Fachbereich Biologie/Chemie, Universität Osnabrück, Abteilung Biochemie, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't