Chemical crosslinking of the subunits of HIV-1 reverse transcriptase

Protein Sci. 1996 Feb;5(2):278-86. doi: 10.1002/pro.5560050212.


The reverse transcriptase (RT) of the human immunodeficiency virus type 1 (HIV-1) is composed of two subunits of 66 and 51 kDa in a 1 to 1 ratio. Because dimerization is a prerequisite for enzymatic activity, interference with the dimerization process could constitute an alternative antiviral strategy for RT inhibition. Here we describe an in vitro assay for the study of the dimerization state of HIV-1 reverse transcriptase based on chemical crosslinking of the subunits with dimethylsuberimidate. Crosslinking results in the formation of covalent bonds between the subunits, so that the crosslinked species can be resolved by denaturing gel electrophoresis. Crosslinked RT species with molecular weight greater than that of the dimeric form accumulate during a 1-15-min time course. Initial evidence suggests that those high molecular weight species represent trimers and tetramers and may be the result of intramolecular crosslinking of the subunits of a higher-order RT oligomer. A peptide that corresponds to part of the tryptophan repeat motif in the connection domain of HIV-1 RT inhibits crosslink formation as well as enzymatic activity. The crosslinking assay thus allows the investigation of the effect of inhibitors on the dimerization of HIV-1 RT.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antiviral Agents / pharmacology*
  • Cross-Linking Reagents / pharmacology*
  • Dimethyl Adipimidate / pharmacology*
  • Dimethyl Suberimidate / pharmacology*
  • HIV Reverse Transcriptase
  • Molecular Sequence Data
  • Molecular Weight
  • Protein Conformation / drug effects*
  • RNA-Directed DNA Polymerase / chemistry*
  • RNA-Directed DNA Polymerase / drug effects*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / drug effects
  • Reverse Transcriptase Inhibitors / pharmacology*
  • Tryptophan / chemistry


  • Antiviral Agents
  • Cross-Linking Reagents
  • Recombinant Fusion Proteins
  • Reverse Transcriptase Inhibitors
  • Dimethyl Adipimidate
  • Dimethyl Suberimidate
  • Tryptophan
  • HIV Reverse Transcriptase
  • RNA-Directed DNA Polymerase