Physicochemical characterization of the recombinant lectin scytovirin and microbicidal activity of the SD1 domain produced in rice against HIV-1
Blanco Perera, Amaya
Shenoy, Shilpa R.
MetadataShow full item record
Scytovirin (SVN) is an HIV-neutralizing lectin that features two structural domains (SD1 and SD2) that bind to HIV-1 envelope glycoproteins. We expressed SD1 in rice seeds as a potential large-scale production platform and confirmed that rice-derived SD1 binds the HIV-1 envelope glycoprotein gp120 in vitro. We analyzed the thermodynamic properties of SD1 compared to full-size SVN (produced in E. coli) by isothermal titration and differential scanning calorimetry to characterize the specific interactions between SVN/SD1 and gp120 as well as to high-mannose oligosaccharides. SVN bound with moderate affinity (K-d = 1.5 mu M) to recombinant gp120, with 2.5-fold weaker affinity to nonamannoside (K-d of 3.9 mu M), and with tenfold weaker affinity to tetramannoside (13.8 mu M). The melting temperature (T-m) of full-size SVN was 59.1 degrees C and the enthalpy of unfolding (Delta H-unf) was 16.4 kcal/mol, but the T-m fell when SVN bound to nonamannoside (56.5 degrees C) and twice as much energy was required for unfolding (Delta H-unf =33.5 kcal/mol). Interestingly, binding to tetramannoside destabilized the structure of SD1 (Delta T-m similar to 11.5 degrees C) and doubled the enthalpy of unfolding, suggesting a dimerization event. The similar melting phenomenon shared by SVN and SD1 in the presence of oligomannose confirmed their conserved oligosaccharide-binding mechanisms. SD1 expressed in transgenic rice was able to neutralize HIV-1 in vitro. SD1 expressed in rice, therefore, is suitable as a microbicide component.
Is part ofPlant Cell Reports, 2022, p.1-11
European research projects
The following license files are associated with this item: