NAD+ mediated differential thermotolerance between chloroplastic and cytosolic L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum (Thunb.) Nakai.
Relative thermotolerance of the enzyme, L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4), from the chloroplastic and cytosolic sources of Diplopterygium glaucum was studied. The purification involved streptomycin sulphate precipitation, ammonium sulphate fractionation, ion-exchange chromatography, and molecular sieve chromatography. After the final chromatography, 16.62% of chloroplastic and 13.47% of cytosolic MIPS could be recovered. Between 15 degrees C and 55 degrees C, the two forms of MIPS exhibited differential thermal stability, which is related to the presence of the MIPS co-factor, NAD+. Added NAD+ increased the lower thermotolerance of the chloroplastic MIPS and the removal of 'built-in' NAD+ decreased the higher thermal stability of the cytosolic MIPS.
Chhetri
D R
DR
Plant Physiology and Biochemistry Laboratory, Post Graduate Department of Botany, Darjeeling Govt. College, Darjeeling, WB, India. munall@sancharnet.in
Adhikari
J
J
Mukherjee
A K
AK
D002736:Chloroplasts / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology*; D004795:Enzyme Stability; D029624:Ferns / Q000201:enzymology*; D006358:Hot Temperature; D007296:Myo-Inositol-1-Phosphate Synthase / Q000737:chemistry* / Q000302:isolation & purification; D009243:NAD / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D013696:Temperature
D010940:Plant Proteins; D009243:NAD; D007296:Myo-Inositol-1-Phosphate Synthase