Heparin mediates binding of S-protein/vitronectin to the envelope glycoprotein of the human immunodeficiency virus and CD4.
Using normal human serum and EDTA-plasma as the two sources of S-protein (vitronectin) in an enzyme-linked immunosorbent assay, we determined that heparin pretreatment of immobilized rgp120 or of immobilized CD4 caused the serum form of S-protein to deposit in a dose-dependent manner. Interestingly, the EDTA-plasma form of S-protein (native form) had little or no interaction with either of the heparin-treated surfaces. Several other sulfated polysaccharides such as dextran sulfate, pentosan polysulfate, heparan sulfate, and fucoidan, likewise mediated the deposition of the serum form S-protein on immobilized rgp120 and CD4. These findings may explain why certain glycosaminoglycans are effective against HIV infectivity in cell culture where the serum form of S-protein is present, yet ineffective in vivo where the native form of S-protein is predominant. The elevated glycosaminoglycan levels in gingival crevicular exudates, coupled with the effects of the serum form of S-protein and salivary-mediated neutralization mechanisms may explain the reduced rates of salivary HIV transmission.
Su
H R
HR
Department of Stomatology, Medical University of South Carolina, Charleston 29425-2230.
Boackle
R J
RJ
D015704:CD4 Antigens / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000378:metabolism*; D015699:HIV Envelope Protein gp120 / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins / Q000378:metabolism; D019096:Vitronectin
D015704:CD4 Antigens; D006023:Glycoproteins; D006025:Glycosaminoglycans; D015699:HIV Envelope Protein gp120; D011994:Recombinant Proteins; D019096:Vitronectin; D006493:Heparin