��ȶ��ø��øѧ��

ժҪ ͨ��봿��øѧ��ʲⶨ ,ȷ��ȶ��ø (p nitrophenylphosphatase)�ǽ��ø�� ,��Բ�λ��þ�� ;��ø��ж��ȵ�� ,��ȶ�� .��ø��Km Ϊ 3 0 31mmol L ,VmaxΪ 313 5 ��mol��min-1��mg-1;��ṹ�д�Լ�� 74 5 %�� ,2 5 5 % ��ת�� .��pH 7 0�� 12 0��Χ��൱�ȶ� .��ø��SDS��Һ��ȶ��Խϲ� ,��TritonX 10 0��Һ�н�Ϊ�ȶ� ,��Tween 2 0��Һ�к��ȶ� .

	Service

	�ѱ��Ƽ��
	��ҵ��
	��ù��
	Email Alert
	RSS
	��
	��Ӿ�

�ؼ���� ȶ��ø øѧ�� ȶ�� ṹ

Abstract�� Thermostable p-nitrophenylphosphatase (TNPPase) had been expressed in E. coli M15, and purified rapidly. It is sensitive to metal chelator and Mg ion is necessary to its activity. TNPPase exhibited a moderate degree of thermostability, and the thermostability of TNPPase increased significantly when treated with 1 mmol/L Mg, Mn, Cu, Ba, Ca, Ni and Zn ions. TNPPase is stable within a wide range of pH (pH 7.0��12.0). It catalyzed the hydrolysis of p-nitrophenylphosphate with a Michaelis constant 3.031 mmol/L and a V max 313.5 ��mol��min -1 ��mg -1 . The ��-helix percentage and ��-turn percentages were 74.5 and 25.5 in the secondary structure of TNPPase, respectively. TNPPase is not stable in SDS solution, but stable in Triton X-100 and Tween 20 solutions.

Keywords�� thermostable nitrophenylphosphatase enzymatic characteristics thermostability metal ion secondary structure

Received 2003-10-06;

��ñ��:

��Ӿ�.��ȶ��ø��øѧ�� [J] �й��ﻯѧ��ѧ��, 2004,V20(05 ): 648-648

.Enzymatic Characteristics of Thermostable p-Nitrophenylphosphatase [J] Chinese Journal of Biochemistry and Molecular Biol, 2004,V20(05 ): 648-648

��ӱ��:

http://cjbmb.bjmu.edu.cn/CN/ �� http://cjbmb.bjmu.edu.cn/CN/Y2004/V20/I05 /648