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Spatholobus parviflorus seed lectin (SPL) is a heterotetrameric lectin, with two α and two β monomers. In the crystal structure of SPL α monomer, two residues at positions 240 and 241 are missing. This region was modeled based on the positional and sequence similarities. The role of metal ions in SPL structure was analyzed by 10 ns molecular dynamics simulation. MD simulations were performed in the presence and absence of metal ions to explain the loss of haemagglutinating property of the lectin due to demetallization. Demetallized structure was found to deviate drastically at the metal binding loop region. Affinity of different sugars like N-acetyl galactosamine (GalNAc), D-galactose and lactose towards the native and demetallized protein was calculated by molecular docking studies. It was found that the sugar binding site got severely distorted in demetallized lectin. Consequently, sugar binding ability of lectin might be decreasing in the demetallized condition. Isothermal titration calorimetric (ITC) analysis of the sugars in the presence of native and demetallized protein confirmed the in silico results. It was observed after molecular dynamics simulations, that significant structural deviations were not caused in the quaternary structure of demetallized lectin. It was confirmed that the structural changes modified the sugar binding ability, as well as sugar specificity of the present lectin. The role of metal ions in sugar binding is described based on the in silico studies and ITC analysis. A comprehensive analysis of the ITC data suggests that the sugar specificity of the metal bound lectin and the loss of sugar specificity due to metal chelation are not linear.

Fifty-two infants (75 ureters) with primary high-grade vesicoureteric reflux (VUR) treated endoscopically by subureteric injection of Polytef paste (STING) were followed up for 1-9 years. There were 30 boys and 22 girls and their ages ranged from 2 to 12 months. Forty-five percent of ureters had grade III VUR, 40% had grade IV and 15% had grade V VUR. Reflux ceased in 49 (65%) ureters after a single injection. Twenty-four percent of ureters in this series required more than one injection of Polytef paste to correct VUR. STING failed to correct VUR in 3 (4%) ureters. Eighty percent of the 49 ureters corrected after a single injection of Polytef required < 0.2 ml of paste per ureter to correct reflux. Ninety-three percent of ureters continue to show absence of VUR 1-9 years after endoscopic correction. Three of the 5 recurrences were only of grade I or grade II severity and required no treatment. No untoward effects were seen in these children with the use of Teflon as an injectable biomaterial. This day care procedure is simple, safe and effective in correcting high grades of reflux in infants.