Document 3325
 DOCN  M94A3325
 TI    Possible cooperativity of tryptase TL2 and CD26 on proteolytic cleavage
       of V3 loop of HIV-1 gp120.
 DT    9412
 AU    Niwa Y; Ohkubo I; Kido H; Inst. for Enzyme Res., Univ. of Tokushima,
       Japan.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):101 (abstract no. PA0021). Unique
       Identifier : AIDSLINE ICA10/94369250
 AB    OBJECTIVES: Infection by HIV-1 is due to virus-cell fusion mediated by
       the viral envelope glycoproteins gp120 and gp41 with CD4 and the other
       cellular cofactors. In this study, possible cooperativity of cellular
       cofactors, such as tryptase TL2 and CD26, on proteolytic cleavage of V3
       loop of HIV-1 gp120 was analyzed. METHODS: Tryptase TL2 and CD26 were
       purified from human CD4+ T cell line, Molt-4, clone 8 cells and from
       human semen, respectively. V3 domain peptide of HTLV-IIIB was
       synthesized and the cysteine residues were oxidized to make loop
       structure. Proteolytic cleavage sites of the V3 loop by tryptase TL2
       and/or CD26 were analyzed by reversed phase HPLC following determination
       of amino acid sequences of the peptide fragments. RESULTS AND
       CONCLUSIONS: Tryptase TL2, a membrane bound serine protease having both
       trypsin- and chymotrypsin-like protease activities, preferentially
       cleaved at sites between R317-G318 and/or F323-V324 and newly appeared
       aminoterminal sequence glycyl proline of the product was further removed
       by incubation with CD26, although CD26 by itself had no proteolytic
       effect on the peptide. The results suggest that tryptase TL2 and CD26 on
       the surface of T lymphocytes, monocytes and macrophages cooperatively
       hydrolyzed V3 loop of HIV-1 gp120 resulting change in tertiary structure
       of the gp120 and the viral internalization.
 DE    Amino Acid Sequence  Antigens, Differentiation, T-Lymphocyte/*METABOLISM
       Binding Sites  Cell Line  Human  HIV Envelope Protein
       gp120/GENETICS/*METABOLISM  HIV Infections/ETIOLOGY
       HIV-1/*METABOLISM/PHYSIOLOGY/PATHOGENICITY  In Vitro  Male  Peptide
       Fragments/GENETICS/*METABOLISM  Semen/METABOLISM  Serine
       Proteinases/*METABOLISM  T4 Lymphocytes/METABOLISM/MICROBIOLOGY  MEETING
       ABSTRACT

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