Document 0252
 DOCN  M94A0252
 TI    Analysis of substrate cleavage by recombinant protease of human T cell
       leukaemia virus type 1 reveals preferences and specificity of binding.
 DT    9412
 AU    Daenke S; Schramm HJ; Bangham CR; Institute of Molecular Medicine,
       Public Health Laboratory, John; Radcliffe Hospital, Headington, Oxford,
       U.K.
 SO    J Gen Virol. 1994 Sep;75 ( Pt 9):2233-9. Unique Identifier : AIDSLINE
       MED/94358721
 AB    Human T cell leukaemia virus type 1 (HTLV-1) protease (PR14) was
       expressed in bacteria and purified by gel filtration. A continuous
       spectrophotometric assay was used to measure the kinetic parameters of
       substrate hydrolysis by PR14. Several peptide substrates containing
       HTLV-1 sequences known to be cleaved by PR14 were used. Cleavage
       analysis showed that the affinity with which PR14 binds these substrates
       is higher than that previously reported for HTLV-1 Gag peptides. Also,
       the affinities of peptides containing the sites involved in autocleavage
       of protease from its precursor are higher than for the peptides
       containing sites required for structural protein maturation. This
       suggests that the autocatalysis of protease from its own precursor has
       priority over other cleavage reactions and supports similar observations
       of an ordered hierarchy of processing events by retroviral proteases. As
       the N- and C-terminal regions of retroviral aspartic proteases are known
       to contribute to stability of the dimer by forming antiparallel
       beta-strands, short peptides corresponding to these terminal sequences
       of HTLV-1 protease were tested for their ability to inhibit cleavage of
       substrates by PR14. Inhibition was seen with a C-terminal peptide
       corresponding exactly to the C-terminal 11 amino acids of the processed
       PR14, whereas a peptide containing a sequence situated further from the
       C terminus was less effective. An inhibitor of the protease of human
       immunodeficiency virus type 1, Ro 31-8959, was found to be a poor
       inhibitor of PR14.
 DE    Amino Acid Sequence  Aspartic Proteinases/*METABOLISM  Binding Sites
       Cloning, Molecular  Comparative Study  Escherichia coli
       HIV-1/*ENZYMOLOGY  HTLV-I/*ENZYMOLOGY  Kinetics  Molecular Sequence Data
       Molecular Weight  Peptide Peptidohydrolases/CHEMISTRY/ISOLATION &
       PURIF/*METABOLISM  Protease Inhibitors/PHARMACOLOGY  Recombinant
       Proteins/CHEMISTRY/ISOLATION & PURIF/METABOLISM  Substrate Specificity
       Support, Non-U.S. Gov't  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).