摘要
本文研究了山药苯丙氨酸解氨酶(PAL)的动力学特性。结果表明,PAL最适底物浓度为1mmol/L,底物浓度过高或过低都对酶活力不利。PAL在硼酸-氢氧化钠缓冲液中适宜的pH范围为7.6～9.2,最适pH有2个:pH8.0和pH8.8。PAL不耐酸碱,尤其不耐碱。PAL适宜的温度范围为35～55℃,最适反应温度为45℃,超过70℃则容易钝化。L-酪氨酸和L-半胱氨酸对PAL活性都有抑制作用,抑制程度随抑制剂浓度增加而增强。L-酪氨酸的抑制作用较强,是PAL的竞争型抑制剂。L-胱氨酸对PAL的活性无影响。
The kinetic characteristics of phenylalanine ammonia-lyase （PAL） in yam was studied. The results suggested that the optimum substrate concentration of PAL was 1 mmol/L. The optimal pH range of PAL in H3BO2-NaOH buffer was from 7.6 to 9.2 and the optimum pH were 8.0, 8.8. PAL couldn＇t bear alkali and acid, especially the former. The optimal temperature range of PAL was 35℃ to 55℃and the optimum temperature was 45℃, its activity was easy blunt above 70℃ It indicated that PAL had some tolerance to high temperature. L-tyrosine and L-cysteine had inhibiting effects on yam PAL and the inhibitory effects increased with the rise in the concentration of the inhibitors. The inhibition by L-tyrosine was more strong and appeared to be competitive. L-cystine was no effect on the activity of the PAL.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2006年第10期36-40,共5页
Food Science
基金
国家农业部"跨越"计划项目(2001-跨-13)
关键词
山药
苯丙氨酸解氨酶
特性
抑制剂
yam phenylalanine ammonia-lyase： charactrics inhibitor
