FLAVIN MONO NUCLEOTIDE PHOSPHATASE FROM GOAT HEART: A FORGOTTEN ENZYME OF AN IMPORTANT METABOLIC PATHWAY

Riboflavin (vitamin B 2 ) is a water soluble vitamin with a key role in maintaining health in humans and animals. It is an easily absorbed micronutrient which exists in microorganisms & animal tissues mainly as coenzyme forms i.e. FMN & FAD. At least fifty five different enzymes in mammals including human need these co-enzymes for their activity, and, the level of FMN and FAD in the tissues at any given time may be an important determinant of tissue health. The present study describes the purification and kinetics of purified FMN-phosphatase from goat heart tissue which was found to be a very good source of the enzyme. Purification of FMN-phosphatase which hydrolyses FMN into riboflavin and inorganic phosphate was done by fractionation using ammonium sulfate followed by overnight dialysis of the fraction at 4 0 C. The dialysate was clarified through centrifugation in cold and was subjected to diethylaminoethyl- cellulose column chromatography. The optimum pH and temperature for the enzyme activity was found to be 5.0 and 40 0 C respectively. The properties of this purified enzyme preparation including Km and substrate specificity were studied. A single band was obtained with enzyme preparation on SDS-polyacrylamide gel electrophoresis and its amino acid sequence analysed.