Synthesis of a Covalently Reactive Antigen Analog Derived from a Conserved Sequence of HIV-1 gp120
Antibodies (Abs) and their light (L) chain subunits are reported to catalyze the cleavage of VIP, the HIV coat proteins gp41 and gpl20, Arg-vasopressin, thyroglobulin, factor VIII, prothrombin and various model peptidase substrates. The serine protease inhibitor diisopropylfluorophosphate (DFP) consistently inhibits the catalytic activity of the Abs, and a serine protease-like catalytic triad in a model proteolytic Ab L chain has previously been deduced from site-directed mutagenesis studies. The catalytic site appears to be germline encoded . In principle, probes that can specifically recognize the active site of serine protease Abs could be applied for the selection of efficient catalytic Abs (CAbs) from display libraries, and perhaps also as the immunogens capable of recruiting the germline encoded Ab variable region genes.