Engineering an obligate domain-swapped dimer of cyanovirin-N with enhanced anti-HIV activity.
The anti-HIV cyanobacterial protein cyanovirin-N can undergo domain swapping to form an intertwined dimer. The dimeric form is stable at low pH and millimolar concentrations. By deleting an amino acid from the hinge linker about which domain swapping occurs, we have constructed an obligate domain-swapped dimer of cyanovirin-N that represents a new tetravalent carbohydrate binding protein that is stable over a large range of pH values. This obligate dimer displays enhanced anti-HIV activity relative to the wild-type cyanovirin-N monomer with an observed 3.5-fold decrease in IC(50) (9nM for the dimer vs 32 nM for the monomer) for inhibition of HIV-1 envelope-mediated cell fusion and, when expressed in Escherichia coli, can be rapidly obtained in >98% purity in a single chromatographic step.
Kelley
Brendan S
BS
Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bethesda, MD 20892-0820, USA.
Chang
Leng Chee
LC
Bewley
Carole A
CA
D019380:Anti-HIV Agents / Q000737:chemistry* / Q000494:pharmacology; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D019281:Dimerization; D015497:HIV-1 / Q000187:drug effects / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D017434:Protein Structure, Tertiary
D019380:Anti-HIV Agents; D001426:Bacterial Proteins; D002352:Carrier Proteins; C107733:cyanovirin N