Atp synthetase

In the present paper, a kinetic study is made of the behavior of a moiety-conserved ternary cycle between the adenine nucleotides. The system con-tains the enzymes S-acetyl coenzyme A synthetase, adenylate kinase and pyruvate kinase, and converts ATP into AMP, then into ADP and finally back to ATP.

16p inspiron33 25-03-2013 49 3   Download

Heat shock inducible lysyl-tRNA synthetase ofEscherichia coli(LysU) is known to be a highly efficient diadenosine 5¢,5¢¢¢-P 1 ,P 4 -tetraphosphate (Ap4A) synthase. However, we use an ion-exchange HPLC technique to demonstrate that active LysU mixtures actually have a dual catalytic activ-ity, initially producing Ap4 A from ATP, before converting that tetraphos-phate to a triphosphate.

11p inspiron33 25-03-2013 38 2   Download

101. Cấu trúc của hormone là những: A. Protein B. Dẫn xuất của acid amine C. Steroid D. A,B,C đều đúng E. A,B,C đều sai. 102. Hormone chỉ có tác dụng khi được gắn với: A. AMP vòng B. Receptor C. ADN D. Adenyl cyclase E. Proteinkinase 103.Adrenalin sau khi gắn vào receptor có tác dụng hoạt hoá trực tiếp: A. ATP B. Adenyl cyclase C. Proteinkinase D. Phosphorylase E. Glycogen synthetase

10p m310dy1ndark 05-03-2013 119 15   Download

Glutathionylspermidine is an intermediate formed in the biosynthesis of trypanothione, an essential metabolite in defence against chemical and oxi-dative stress in the Kinetoplastida. The kinetic mechanism for glutathionyl-spermidine synthetase (EC 6.3.1.8) from Crithidia fasciculata (CfGspS) obeys a rapid equilibrium random ter-ter model with kinetic constants KGSH= 609lm, KSpd= 157lmand KATP= 215lm.

14p vinaphone15 28-02-2013 56 5   Download

Mycobacterium tuberculosis glutamyl–tRNA synthetase (Mt-GluRS), encoded by Rv2992c, was overproduced inEscherichia colicells, and puri-fied to homogeneity. It was found to be similar to the other well-character-ized GluRS, especially the E. colienzyme, with respect to the requirement for bound tRNA Glu to produce the glutamyl-AMP intermediate, and the steady-state kinetic parameterskcat (130 min )1 ) and KMfor tRNA (0.7 lm) and ATP (78lm), but to differ by a one order of magnitude higher KM value forl-Glu (2.7 mm). ...

15p vinaphone15 27-02-2013 31 2   Download

The ATP–pyrophosphate exchange reaction catalyzed by Arg-tRNA, Gln-tRNA and Glu-tRNA synthetases requires the assistance of the cognate tRNA. tRNA also assists Arg-tRNA synthetase in catalyzing the pyro-phosphorolysis of synthetic Arg-AMP at low pH. The mechanism by which the 3¢-end A76, and in particular its hydroxyl group, of the cognate tRNA is involved with the exchange reaction catalyzed by those enzymes has yet to be established.

17p vinaphone15 25-02-2013 55 2   Download

The structural basis for the homotropic inhibition of pantothenate synthe-tase by the substrate pantoate was investigated by X-ray crystallography and high-resolution NMR spectroscopic methods. The tertiary structure of the dimeric N-terminal domain of Escherichia colipantothenate synthetase, determined by X-ray crystallography to a resolution of 1.7 A˚ , showed a second molecule of pantoate bound in the ATP-binding pocket.

16p mobifone23 18-01-2013 51 4   Download

Studies of ion pumps, such as ATP synthetase and Ca 2+ -ATPase, have a long history. The crystal structures of several kinds of ion pump have been resolved, and provide static pictures of mechanisms of ion transport.

7p cosis54 04-01-2013 42 2   Download

Cấu trúc của hormone là những: A. Protein B. Dẫn xuất của acid amine C. Steroid D. A,B,C đều đúng E. A,B,C đều sai. 102. Hormone chỉ có tác dụng khi được gắn với: A. AMP vòng B. Receptor C. ADN D. Adenyl cyclase E. Proteinkinase 103.Adrenalin sau khi gắn vào receptor có tác dụng hoạt hoá trực tiếp: A. ATP B. Adenyl cyclase C. Proteinkinase D. Phosphorylase E. Glycogen synthetase 104.Vùng dưới đồi tiết ra: A. Các RF B. Các IF C. GH D. A và B E. A, B và C 105.Tuyến yên tiết ra: A....

10p buddy7 29-06-2011 115 12   Download

Lục lạp là bào quan phổ biến và đóng vai trò quan trọng trong thế giới thực vật, vì nó thực hiện chức năng quang hợp biến năng lượng của ánh sáng mặt trời thành năng lượng hoá học để cung cấp cho toàn bộ thế giới sinh vật. Lục lạp cũng có cấu trúc màng hai lớp. Màng ngoài rất dễ thấm, màng trong rất ít thấm, giữa màng ngoài và màng trong có một khoang giữa màng.

8p heoxinhkute5 09-11-2010 387 96   Download