1Department of Biotechnology, Gandhi Krishi Vignyan Kendra, Bangalore-560065, India.
2Department of Crop Physiology, Gandhi Krishi Vignyan Kendra, Bangalore-560065, India.
3Dry Farm, University of Agricultural Sciences, Gandhi Krishi Vignyan Kendra, Bangalore-560065, India.
4Indian Agricultural Research Institute, New Delhi-110 012, India.
A red fluorescent protein (RFP) from silkworm gut juice was isolated and purified by a combination of ammonium sulfate fractionation and gel filtration chromatography. The elution profile of gel filtration chromatography on Sephadex G-100 showed three peaks at 280 nm, of this only one peak showed high absorbance both at 280 nm and 605 nm, which is characteristic of RFP. Fractions constituting the major peak showed red fluorescence under UV light. Electrophoretic analysis on SDS-PAGE revealed that RFP is a single protein band having molecular weight of 66 kDa. Antiviral activity of RFP against nuclear polyhedrosis virus (NPV) through bioassay studies revealed that larvae treated with NPV + RFP reduces the percent mortality to 44% compared tothe larvae treated with NPV + BSA (reference protein) having 84% mortality. Immuno characterization of purified RFP showed that RFP content in the digestive juice of silkworm depends on the quality of mulberry leaves. Increased application of nitrogen and potassium to mulberry increased the RFP content in silkworm.
Red fluorescent protein, antiviral activity, nuclear polyhedrosis virus (NPV)
