PARTIAL-PURIFICATION AND CHARACTERIZATION OF FRUCTOKINASE FROM DEVELOPING TAPROOTS OF SUGAR-BEET (BETA-VULGARIS)

被引:29
|
作者
CHAUBRON, F [1 ]
HARRIS, N [1 ]
ROSS, HA [1 ]
DAVIES, HV [1 ]
机构
[1] SCOTTISH CROP RES INST, DEPT CELLULAR & ENVIRONM PHYSIOL, DUNDEE DD2 5DA, SCOTLAND
关键词
BETA VULGARIS; SUGAR-BEET; FRUCTOKINASE; SUGAR;
D O I
10.1016/0168-9452(95)04206-A
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Fructokinase (FK) has been purified from developing sugar beet (Beta vulgaris L.) taproots by ion exchange chromatography and gel filtration. One major isoform was identified. The protein appears to be a dimer (M(r) 38000). Kinetically, the purified sugar beet fructokinase has a pH optimum of 8.5 and a high specificity for fructose (K-m = 0.068 mM). The enzyme can utilise a range of nucleotide triphosphates, although ATP is the most effective. Sugar beet fructokinase is inhibited by fructose concentrations in excess of 0.6 mM. Fructose-6-phosphate and Mg ADP are also inhibitory, but at relatively high concentrations. K+ at 10 mM stimulates activity by 30%. Fructokinase activity and the level of FK protein remain high throughout taproot development. Tissue-blots showed that high levels of FK protein were associated with conducting tissues.
引用
收藏
页码:181 / 186
页数:6
相关论文
共 50 条