Document 1926
 DOCN  M94A1926
 TI    Conformation-dependent GP120 antibodies detected in natural infection
       recognize epitopes with common structural constraints.
 DT    9412
 AU    Lee TH; Lee CN; Syu WJ; Essex M; Harvard School of Public Health,
       Department of Cancer Biology,; Boston, MA.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):42 (abstract no. 141A). Unique
       Identifier : AIDSLINE ICA10/94370649
 AB    The envelope glycoprotein gp120 of HIV-1 is known for its variability.
       Despite this, there are two structural features that are highly
       conserved by all genetic subtypes. First, there are 18-20 cysteine
       residues that are believed to form 9-10 pairs of disulfide bonds in the
       mature gp120. These cysteine residues are located in comparable regions
       with fairly constant spacing in all known HIV-1 isolates. The highly
       conserved cysteine residues have crucial roles in maintaining the
       conformation of those epitopes recognized by conformation-dependent
       gp120 antibodies detected in HIV-1 infected people. The other feature
       common to all HIV-1 isolates is the presence of a large number of
       N-linked glycosylation sites. It is believed that approximately 50% of
       the molecular mass of gp120 is contributed by the carbohydrate. We have
       reported previously that most of these N-linked sugars are not conserved
       for virus infectivity per se, and proposed that N-linked sugars limit
       the immunogenicity of gp120. We report here that small deletions and
       point mutations introduced to different regions of gp120 were sufficient
       to abolish the binding of conformation-dependent gp120 antibodies
       detected in HIV-1 infected people. As mutations introduced span several
       regions of gp120, this implies that gp120 is a tightly folded molecule.
       One interpretation of our findings is that all conformational epitopes
       recognized by naturally developed gp120 antibodies are dictated by
       common structural constraints. Alternatively, our finding may suggest
       limited recognition of conformational epitopes of gp120 in HIV-1
       infection.
 DE    Antigenic Determinants/*ULTRASTRUCTURE  Carbohydrate Conformation
       Cysteine/METABOLISM  Glycosylation  Human  HIV Envelope Protein
       gp120/GENETICS/*IMMUNOLOGY/ULTRASTRUCTURE  HIV-1/*IMMUNOLOGY  Nucleic
       Acid Conformation  Regulatory Sequences, Nucleic Acid  MEETING ABSTRACT

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