Isolation and partial purification of an enzyme catalyzing the formation of
<i>O</i>
-xylosylzeatin in
<i>Phaseolus vulgaris</i>
embryos
作者:Janet E. Turner、David W. S. Mok、Machteld C. Mok、Gordon Shaw
DOI:10.1073/pnas.84.11.3714
日期:1987.6
ribonucleoside. The enzyme (UDP-xylose:zeatin O-xylosyltransferase, EC 2.4.2.-) has high affinity for trans-zeatin (K(m) 2 muM) and dihydrozeatin (K(m) 10 muM) but does not recognize cis-zeatin or ribosylzeatin. The molecular weight of the enzyme is approximately 50,000 and the pH optimum of the reaction is 8-8.5. Under comparable isolation and reaction conditions, similar enzyme activity could not
催化细胞分裂素代谢物的形成的酶,玉米素的O-戊糖基衍生物[Lee,YH,Mok,MC,Mok,DWS,Griffin,DA&Shaw,G.(1985)植物生理学。77,635-641]是从菜豆胚中分离出来的。在所有测试的潜在戊糖供体中,UDP-木糖是酶识别的唯一底物。这表明先前获得的O-戊糖基衍生物是O-木糖基玉米蛋白及其核糖核苷。该酶(UDP-木糖:玉米素O-木糖基转移酶,EC 2.4.2.-)对反式玉米素(K(m)2 muM)和二氢玉米素(K(m)10 muM)具有高亲和力,但不识别顺式玉米蛋白或核糖基玉米蛋白。该酶的分子量约为50,000,反应的最佳pH为8-8.5。在可比的分离和反应条件下,