Document 0367
 DOCN  M9490367
 TI    Kinetics and mechanism of autoprocessing of human immunodeficiency virus
       type 1 protease from an analog of the Gag-Pol polyprotein.
 DT    9411
 AU    Louis JM; Nashed NT; Parris KD; Kimmel AR; Jerina DM; Laboratory of
       Cellular and Developmental Biology, National; Institute of Diabetes and
       Digestive and Kidney Diseases, National; Institutes of Health, Bethesda,
       MD 20892.
 SO    Proc Natl Acad Sci U S A. 1994 Aug 16;91(17):7970-4. Unique Identifier :
       AIDSLINE MED/94336669
 AB    Upon renaturation, the polyprotein MBP-delta TF-Protease-delta Pol,
       consisting of HIV-1 protease and short native sequences from the
       trans-frame protein (delta TF) and the polymerase (delta Pol) fused to
       the maltose-binding protein (MBP) of Escherichia coli, undergoes
       autoprocessing to produce the mature protease in two steps. The initial
       step corresponds to cleavage of the N-terminal sequence to release the
       protein intermediate Protease-delta Pol, which has enzymatic activity
       comparable to that of the mature enzyme. Subsequently, the mature enzyme
       is formed by a slower cleavage at the C terminus. The rate of increase
       in enzymatic activity is identical to that of the appearance of
       MBP-delta TF and the disappearance of the MBP-delta TF-Protease-delta
       Pol. Initial rates are linearly dependent on the protein concentration,
       indicating that the N-terminal cleavage is first-order in protein
       concentration. The reaction is competitively inhibited by pepstatin A
       and has a pH rate profile similar to that of the mature enzyme. These
       results and molecular modeling studies are discussed in terms of a
       mechanism in which a dimeric full-length fusion protein must form prior
       to rate-limiting intramolecular cleavage of the N-terminal sequence that
       leads to an increase in enzymatic activity.
 DE    Amino Acid Sequence  Carrier Proteins/BIOSYNTHESIS  Escherichia
       coli/METABOLISM  Fusion Proteins, gag-pol/*METABOLISM  Hydrogen-Ion
       Concentration  HIV Protease/*BIOSYNTHESIS/CHEMISTRY/METABOLISM
       HIV-1/*ENZYMOLOGY  Kinetics  Models, Molecular  Molecular Sequence Data
       Oligopeptides/METABOLISM  Pepstatins/PHARMACOLOGY  Protein Folding
       Protein Structure, Secondary  Substrate Specificity  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
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