Linked Life Data

8626801

Source:http://linkedlifedata.com/resource/pubmed/id/8626801

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1996-6-21
pubmed:abstractText
Recently, the mechanism of autoprocessing of the protease (PR) of the human immunodeficiency virus type 1 from the model polyprotein, MBP-DeltaTF-PR-DeltaPol, which contains the protease linked to short native flanking sequences (DeltaTF and DeltaPol) fused to the maltose binding protein (MBP) of Escherichia coli, was reported (Louis, J. M., Nashed, N. T., Parris, K. D., Kimmel, A. R., and Jerina, D. M. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 7970-7974). According to this mechanism, intramolecular cleavage of the N-terminal strands of the dimeric MBP-DeltaTF-PR-DeltaPol protein leads to the formation of the PR-DeltaPol intermediate, which is subsequently converted to the mature protease by cleavage of the C-terminal strands. We now report the purification and characterization of the PR-DeltaPol intermediate and the kinetics of its processing to the mature protease. Unlike the MBP-DeltaTF-PR-DeltaPol precursor, PR-DeltaPol has proteolytic activity similar to that of the mature enzyme at pH 5.0. The pH rate profile for kcat/Km is similar to that of the mature protease above pH 4.0. Although the PR-DeltaPol is more sensitive than the mature protease toward denaturing reagents, both the enzymatic activity and the intrinsic fluorescence of PR-DeltaPol are linearly dependent on the protein concentration, indicating that the protein is largely in its dimeric form above 10 nM. In contrast to the first-order kinetics observed for the proteolytic reaction at the N terminus of the protease, the proteolytic reaction at the C terminus of the protease is second order in protein concentration. These results are discussed in terms of a mechanism in which the C-terminally located DeltaPol peptide chains are cleaved intermolecularly to release the mature protease.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4477-81
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
A transient precursor of the HIV-1 protease. Isolation, characterization, and kinetics of maturation.
pubmed:affiliation
Molecular Mechanisms of Development Section, Laboratory of Cellular and Developmental Biology, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.