Fig. 1. Sequence alignment between the two domains of SVN. Amino acids are represented by single-letter codes. Identical sites are represented by ‘=’. Conserved sites are represented by ‘*’. Disulfide bonds are marked with solid lines above the sequence.

Fig. 2. Amino acids sequences of SVN mutants. The cysteines at positions 7 and 55 of the SVN sequence have been mutated into serine.

Fig. 3. SDS-PAGE and immunoblot analysis of purified SVN, SD1 and SD2. (A) Coomassie blue-stained gel of the purified peptides. (B) Immunoblot analysis of an identical gel with rabbit anti-scytovirin polyclonal antibodies [Lane 1: SVN, Lane 2: SD1 and Lane 3: SD2].

Fig. 4. Disulfide-bonding pattern of recombinant SD1 and SD2. The values of trypsin-digested SD1 or SD2 were input into the software (http://sx102a.niddk.nih.gov/peptide/) to establish the disulfide-bonding pattern.

Fig. 5. ELISA study of the concentration-dependent binding of recombinant SVN or SD1 to (A) gp120 and (B) gp41. Glycosylated gp120 or gp41 was bound to an ELISA plate and then treated with SVN or SD1. The amount of bound SVN or SD1 was determined by absorbance at 450 nm as described in Section 2. Results are the average absorbance at 450 nm (±S.D.) from triplicate wells.

Fig. 6. ELISA study of recombinant SVN and mutants to (A) gp120 and (B) gp41. Glycosylated gp120 or gp41 was bound to an ELISA plate and then treated with SVN or mutants. The amount of bound SVN or mutants was determined by absorbance at 450 nm as described in the Experimental section. All data are corrected for background antibody absorption in the absence of captured protein (typically < 0.1 OD₄₅₀). Results are the average absorbance at 450 nm (±S.D.) from triplicate wells.

Fig. 7. Concentration-dependent inhibition of SD1 binding to HIV envelope protein gp41 by the high-mannose oligosaccharide Man-8. Points are the averages ± standard deviations of three replicate determinations.

Production, molecular weight and anti-HIV activities of SVN peptides