Purification and characterization of NAD (P) H quinone reductase from the latex of Hevea brasiliensis Müll.-Arg.(Euphorbiaceae) Academic Article uri icon

abstract

  • Abstract NAD (P) H quinone reductase [NAD (P) H–QR] present in the latex of Hevea brasiliensis Müll.-Arg.(Euphorbiaceae) was purified to homogeniety from the B-serum fraction obtained by freeze-thawing of the bottom fraction of ultracentrifuged fresh latex. The purification protocol involved acetone fractionation, heat treatment, ion exchange chromatography and affinity chromatography. The M r determined by SDS–PAGE for the protein subunit was 21 kDa, and the molecular mass of the native enzyme estimated by gel filtration was 83 kDa, indicating that the native enzyme is a homotetramer. The enzyme showed pH stability over a range of 6 to at least 10 (with an optimum at pH 8) and thermal stability up to 80° C. High NAD (P) H–QR activity (70%) was still retained after 10 h of preincubation at 80° C. A comparable substrate specificity for this enzyme was observed …

publication date

  • September 1, 2002