Báo cáo khoa học: Spectroscopic and kinetic properties of the horseradish peroxidase mutant T171S Evidence for selective effects on the reduced state of the enzyme potx

... Spectroscopic and kinetic properties of the horseradish peroxidase mutant T171S Evidence for selective effects on the reduced state of the enzyme Barry D. Howes 1 , ... and specific to the reduced state of the enzyme. The Fe(II) state of the enzyme has features in common with both the Phe221Met mutant and Ca-depleted protei...

Ngày tải lên: 07/03/2014, 21:20

... of the beneficial effects of ACh has been challenged by accumulating evidence of the sparseness of cholinergic innervation of the ventricular myo- cardium, except for the specialized conduction ... intracellular pathways for ACh production in cardiomyocytes. Second, we determined the intracellular concentrations and loca- tions of ACh. Third, we examined the...

Ngày tải lên: 23/03/2014, 05:22

... to the heme [23,24]. The conformational adaptability of HSA involves more than the immediate vicinity of the binding site(s), affecting both the structure and the ligand-binding properties of the ... þ36c 2 D 2 s 2 v  ð11Þ where N is the molar concentration of Fe(III)heme, q is the number of water molecules coordinated to the metal ion, r is the average di...

Ngày tải lên: 23/03/2014, 04:21

... probing the thermodynamic and kinetic consequences of these mutations. We have studied the thermodynamic and kinetic properties of the isolated FAD domain of rat nNOS and three mutant forms. The isolated ... the thermodynamic properties of the FAD and also their consequences on the kinetics of FAD reduction. The thermodynamic properties of th...

Ngày tải lên: 30/03/2014, 14:20

... pH selectively inhibited activation of anionic trypsinogen. Under both conditions, the concentration of cationic trypsinogen seemed to determine the rate of autoactivation and the final levels of ... demonstrated. In these conditions, the pro- portion of anionic and cationic isoforms becomes reversed, and anionic trypsinogen dominates pancreatic secretions. In acute pan...

Ngày tải lên: 17/03/2014, 03:20

... 530 and 559 nm, and those of the Fe(II)–CO complex were at 422, 538 and 566 nm. On the other hand, optical absorption spectra of the Fe(III), Fe(II) and Fe(II)–CO complexes of the PAS-A domain of ... that the rate constant was similar to those of other heme proteins (Table 4). On the basis of these association and dissociation rate constants, we estimated...

Ngày tải lên: 30/03/2014, 11:20

... alternative conformations. The pseudorotation angles for the uridine of N-acyl- sulfonamide 7 were found in both the C 3 ¢-endo (N) conformation and the O 4 ¢-endo conformation, whereas the C 3 ¢-endo conformation ... hydrogen bonds with the enzyme, and O 2 ¢ forms two additional hydrogen bonds in each of its conformations. Thus, in either observed conformation of N-a...

Ngày tải lên: 14/02/2014, 22:20

... that the enzyme has at least three effector sites, one for ATP, one for ADP and one for BPG [5,12]. On the basis of the results obtained from crystallization of a truncated form of cN-II [11], we constructed ... binding of adenine (F127E and M436W) had no effect on the functional characteristics of the enzyme, except for an increase in the K 50 for A...

Ngày tải lên: 15/02/2014, 01:20

... confor- mation change, then allowing the purine base to bind in accordance with the mechanism of human HPRT [19,25]. This conclusion can be made based on the lack of thermal shifts when only the ... result of the high concentration of Ca 2+ present in the crys- tallization buffer. The geometry is consistent with a Ca 2+ ion coordinated by Glu141, Asp142, 2¢ and 3¢OH...

Ngày tải lên: 15/02/2014, 01:20

... at a final concentration of 1 mm. Bacterial strains and culture conditions E. coli strain DH5a was used for the cloning and amplifica- tion of all constructed plasmids. Overexpression of target genes ... ones (Glu and Asp), while mutation of Phe63 into other amino acids allowed the enzyme to retain similar activity. Leu92 is one of the major constituents of the hyd...

Ngày tải lên: 18/02/2014, 08:20