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Intrinsic activity of precursor forms of HIV‐1 proteinase
Author(s) -
Phylip Lowri H.,
Mills John S.,
Parten Benne F.,
Dunn Ben M.,
Kay John
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)81524-p
Subject(s) - chemistry , proteinase 3 , human immunodeficiency virus (hiv) , biochemistry , virology , biology , immunology , antibody , autoantibody
The wild‐type ‐Phe*Pro‐ bond located at the N‐terminus of the mature aspartic proteinase of HIV‐1 was replaced by ‐Ile‐Pro‐ or ‐Val‐Pro‐. By this means, processing at this cleavage junction was prevented and so, extended or precursor forms of HIV‐proteinase were generated. These constructs were expressed in Escherichia coli , purified therefrom, and their specificity, activity at different pH values and susceptibility to the potent inhibitor, Ro31‐8959, was assessed. A hitherto unobserved cleavage junction (at ∼Ala‐Phe*Leu‐Gln∼) in the frame‐shift region of the gag‐pol viral penome was identified and confirmed by demonstrating cleavage of a synthetic peptide corresponding to this region. The implications for viral replication of self‐processing at neutral pH by proteinase whilst still present (in a precursor form) as a component of the polyprotein are considered; such reactions, however, are still blocked even at pH values as high as 8.0 by Ro31‐8959.