PT  - JOURNAL ARTICLE
AU  - Barry R. O'Keefe
AU  - Shilpa R. Shenoy
AU  - Dong Xie
AU  - Wentao Zhang
AU  - Jeffrey M. Muschik
AU  - Michael J. Currens
AU  - Irwin Chaiken
AU  - Michael R. Boyd
TI  - Analysis of the Interaction between the HIV-Inactivating Protein Cyanovirin-N and Soluble Forms of the Envelope Glycoproteins gp120 and gp41
AID  - 10.1124/mol.58.5.982
DP  - 2000 Nov 01
TA  - Molecular Pharmacology
PG  - 982--992
VI  - 58
IP  - 5
4099  - http://molpharm.aspetjournals.org/content/58/5/982.short
4100  - http://molpharm.aspetjournals.org/content/58/5/982.full
SO  - Mol Pharmacol2000 Nov 01; 58
AB  - The novel virucidal protein cyanovirin-N (CV-N) binds with equally high affinity to soluble forms of either H9 cell-produced or recombinant glycosylated HIV-1 gp120 (sgp120) or gp160 (sgp160). Fluorescence polarization studies showed that CV-N is also capable of binding to the glycosylated ectodomain of the HIV-envelope protein gp41 (sgp41) (as well as SIV glycoprotein 32), albeit with considerably lower affinity than the sgp120/CV-N interaction. Pretreatment of CV-N with either sgp120 or sgp41 abrogated the neutralizing activity of CV-N against intact, infectious HIV-1 virions. Isothermal calorimetry and optical biosensor binding studies showed that CV-N bound to recombinant sgp120 with a K d value ranging from 2 to 45 nM and to sgp41 with a K d value of 606 nM; furthermore, they indicated an approximate 5:1 stoichiometry for CV-N binding to sgp120 and a 1:1 stoichiometry for CV-N binding to sgp41. Circular dichroism studies additionally illuminated the binding of CV-N with both sgp120 and sgp41, providing the first direct evidence that conformational changes are a consequence of CV-N interactions with both HIV-1 envelope glycoproteins.