CAJ | 학술논문

为了探索几种蛋白质变性剂对多聚半乳糖醛酸酶的作用效果,以水溶性低分子量壳寡糖(COS,分子量约5000)作为修饰剂对已纯化的多聚半乳糖醛酸酶(PG)进行化学修饰,得到纯化的化学修饰酶(COS-PG),然后,测定不同蛋白变性剂(尿素、盐酸胍、SDS和苯酚)对纯化的PG和COS-PG催化活性的影响.结果表明,修饰后COS-PG的比活性是340.10 U?(mg protein)?1,比修饰前的PG提高了153%,COS-PG的糖含量比PG提高了43.11%,COS-PG的氨基修饰率为32.85%.SDS(十二烷基硫酸钠)、苯酚对PG和COS-PG活性有抑制作用,1 mmol?L?1的SDS分别抑制了PG和COS-PG活性的80.99%和91.14%.10 mmol?L?1的苯酚分别抑制了PG和COS-PG活性的34.08%和32.70%.低浓度的尿素和盐酸胍对PG有激活作用,5 mmol?L?1的尿素使PG活性提高157.79%,3 mmol?L?1的尿素使COS-PG 的活性提高67.32%.2 mmol?L?1的盐酸胍使PG活性提高57.64%,1 mmol?L?1的盐酸胍使COS-PG的活性提高5.76%.
위료탐색궤충단백질변성제대다취반유당철산매적작용효과,이수용성저분자량각과당(COS,분자량약5000)작위수식제대이순화적다취반유당철산매(PG)진행화학수식,득도순화적화학수식매(COS-PG),연후,측정불동단백변성제(뇨소、염산고、SDS화분분)대순화적PG화COS-PG최화활성적영향.결과표명,수식후COS-PG적비활성시340.10 U?(mg protein)?1,비수식전적PG제고료153%,COS-PG적당함량비PG제고료43.11%,COS-PG적안기수식솔위32.85%.SDS(십이완기류산납)、분분대PG화COS-PG활성유억제작용,1 mmol?L?1적SDS분별억제료PG화COS-PG활성적80.99%화91.14%.10 mmol?L?1적분분분별억제료PG화COS-PG활성적34.08%화32.70%.저농도적뇨소화염산고대PG유격활작용,5 mmol?L?1적뇨소사PG활성제고157.79%,3 mmol?L?1적뇨소사COS-PG 적활성제고67.32%.2 mmol?L?1적염산고사PG활성제고57.64%,1 mmol?L?1적염산고사COS-PG적활성제고5.76%.
In order to investigate the effects of several protein denaturants on the activity of polygalacturonase and modified polygalacturonase, the low molecular chitosan (COS, MW about 5000) was used to modify the purified polygalacturonase (PG) to get chemically modified polygalacturonase (COS-PG) and four denaturants (urea, guanidine hydrochloride, sodium dodecyl sulphate, phenol) were used separately for the measurement of their influences on the catalytic activites of PG and COS-PG. It was found that, after modification, the activity of COS-PG is 340.10 U?(mg protein)?1, which is 153% higher than that of PG, and the polycarbohydrate content in COS-PG is 43.11% higher than that of PG. The amino modification ratio of COS-PG is 32.85%. Sodium dodecyl sulphate (SDS) and phenol can inhibite the activities of PG and COS-PG. SDS of 1 mmol?L?1 inhibites the activities of PG and COS-PG by 80.99% and 91.14%, respectively, and 10 mmol?L?1 phenol inhibites the activities of PG and COS-PG by 34.08% and 32.70%, respectively. Urea and guanidine hydrochloride in low concentrations can activate PG and COS-PG. Urea of 5 mmol?L?1 increases the activity of PG by 157.79%, and urea of 3 mmol?L?1 increases the activity of COS-PG by 67.32%. Guanidine hydrochloride of 2 mmol?L?1 increases the activity of PG by 57.64%, and guanidine hydrochloride of 1 mmol?L?1 increases the activity of COS-PG by 5.76%.