NLM AIDSLINE Monomer-trimer equilibrium of the ectodomain of SIV gp41: insight into
the mechanism of peptide inhibition of HIV infection.
Caffrey M; Kaufman J; Stahl S; Wingfield P; Gronenborn AM; Clore GM
March 30, 2000
Unique Identifier : AIDSLINE MED/99421335
The monomer-trimer equilibrium of the ectodomain of SIV gp41 (residues
27-149, e-gp41) has been characterized by analytical
ultracentrifugation, circular dichroism (CD), and NMR spectroscopy.
Based on analytical ultracentrifugation experiments performed at
different rotor speeds and protein concentrations, the equilibrium
association constant for the SIV e-gp41 trimer is 3.1 x 10(11) M(-2).
The presence of intermolecular nuclear Overhauser effects in a mixture
of 12C and 13C-labeled e-gp41 prepared under nondenaturing conditions
unambiguously demonstrates that there is a dynamic equilibrium between
the monomer and trimer. The CD spectra taken as a function of SIV e-gp41
concentration suggest that the helical content of the