Abstract
We have analyzed the binding of soluble CD4 (sCD4) to human immunodeficiency virus type 1 (HIV-1) virions (isolates IIIB and RF) at 4 and 37 degrees C by using a combination of gel exclusion chromatography and enzyme-linked immunosorbent assay detection systems. The sCD4 binding curve at 37 degrees C indicates that the affinity of the interaction of sCD4 with gp120 on the virion surface is indistinguishable from the affinity of sCD4 for the equivalent concentration of soluble gp120. At 4 degrees C, however, the affinity of sCD4 for virion-bound gp120 but not for soluble gp120 is reduced by about 20-fold. Binding of sCD4 (greater than 0.2 microgram/ml) to virions at 37 degrees C but not 4 degrees C induces the rapid dissociation of a major proportion of gp120 from gp41 on the virion surface. This dissociation requires occupancy by sCD4 of multiple (probably two) binding sites on a gp120-gp41 oligomer. At 37 degrees C there are two components to the neutralizing action of sCD4 on HIV-1; reversible, competitive inhibition at low sCD4 concentrations (less than 0.2 microgram/ml) and essentially irreversible inhibition due to gp120 loss at higher sCD4 concentrations. At 4 degrees C, sCD4 neutralizes HIV infectivity by competitive inhibition alone. These findings may have implications for the HIV-CD4+ cell binding and fusion reactions and the mechanism by which sCD4 blocks infectivity.
Bibliography
Moore, J. P., McKeating, J. A., Norton, W. A., & Sattentau, Q. J. (1991). Direct measurement of soluble CD4 binding to human immunodeficiency virus type 1 virions: gp120 dissociation and its implications for virus-cell binding and fusion reactions and their neutralization by soluble CD4. Journal of Virology, 65(3), 1133â1140.
Dates
Type | When |
---|---|
Created | 5 years, 7 months ago (Jan. 6, 2020, 11:03 a.m.) |
Deposited | 3 years, 5 months ago (March 4, 2022, 7:22 p.m.) |
Indexed | 11 months, 2 weeks ago (Sept. 5, 2024, 11:07 a.m.) |
Issued | 34 years, 5 months ago (March 1, 1991) |
Published | 34 years, 5 months ago (March 1, 1991) |
Published Print | 34 years, 5 months ago (March 1, 1991) |
@article{Moore_1991, title={Direct measurement of soluble CD4 binding to human immunodeficiency virus type 1 virions: gp120 dissociation and its implications for virus-cell binding and fusion reactions and their neutralization by soluble CD4}, volume={65}, ISSN={1098-5514}, url={http://dx.doi.org/10.1128/jvi.65.3.1133-1140.1991}, DOI={10.1128/jvi.65.3.1133-1140.1991}, number={3}, journal={Journal of Virology}, publisher={American Society for Microbiology}, author={Moore, J P and McKeating, J A and Norton, W A and Sattentau, Q J}, year={1991}, month=mar, pages={1133–1140} }