(1) The transition was characterized by a single first order rate constant (kobs,i) which was independent of enzyme concentration.
(2) Knowledge of the salt dependences of ka and of the observed equilibrium constance Kobs of the ligand-nucleic acid interaction should usually be sufficient to determine whether a screening controlled mechanism or a pre-equilibrium mechanism is suitable to describe the process.
(3) A log kobs versus pH profile for the approach to the ionization equilibrium was determined, and a mechanism consistent with the profile was postulated.
(4) In the absence of cyanide, ferrocytochrome a3 appears at a rate (kobs) of 0.016 s-1.
(5) Above 25 microM AT.H complex, an increasing dead time displacement of p-aminobenzamidine and a downward deviation of kobs from the initial linear dependence on AT.H complex concentration were found, reflecting the saturation of an intermediate Xa.AT.H complex with a KD of 200 microM and a limiting rate of Xa-AT product complex formation of 140 s-1.
(6) At pH 7.8, the apparent single rate constant for association (kobs) at 4 degrees C was 4.72 x 10(+5).M-1.min-1.
(7) Thus, under pseudo-first order conditions ([AT]o, [H]o much greater than [T]o much less than [P]o), the observed thrombin inactivation rate constant (kobs) exhibited a saturable dependence on [AT]o or [H]o when [H]o much less than KT,H, reflecting a KAT,H (0.25 microM) similar to that directly determined by equilibrium binding.
(8) The nature of the anion often has a major effect on the magnitude of the equilibrium constant (Kobs) and rate constant (kobs) of protein-DNA interactions, but a minor effect on SKobs and Skobs, which are dominated by the cation stoichiometry.
(9) The rate constant (kobs) for loss of ADP activation exhibits a nonlinear dependence on 2-BDB-TAMP concentration, suggesting a reversible binding of reagent (KR = 0.74 mM) prior to irreversible modification.
(10) The kobs max value in tissues from insulin-dependent diabetic patients was significantly greater than that in tissues from either noninsulin-dependent diabetics or nondiabetics.
(11) Reduction by lumiflavin semiquinone followed single exponential kinetics and the observed rate constant (kobs) was linearly dependent on protein concentration (k = 1.8 X 10(7) M-1s-1 heme-1).
(12) At 0.25 M-KX, the increase in Kobs for Osym is observed to be approximately 40-fold, whereas for non-operator DNA the increase in Kobs is estimated by extrapolation to be approximately 300-fold.
(13) The Kobs of this reaction reflects the difference between the observed standard free energy change (delta G-oobs) for the hydrolysis of acetylcholine and the delta G-oobs for the hydrolysis of acetyl-CoA.
(14) The observed equilibrium constants (Kobs) of the creatine kinase (EC 2.7.3.2), myokinase (EC 2.7.4.3), glucose-6-phosphatase (EC 3.1.3.9), and fructose-1,6-diphosphatase (EC 3.1.3.11) reactions have been determined at 38 degrees C, pH 7.0, ionic strength 0.25, and varying free magnesium concentrations.
(15) Stopped-flow spectrophotometry also showed that electron transfer from the Fe-protein to the MoFe-protein in states E0 and E1H occurs at the same rate (kobs.
(16) A study of kobs vs pH suggests this active-site lysine has a pKa of 8.1 and a pH-independent rate constant of inactivation of 47,700 M-1 min-1.
(17) At all temperatures, the pH strongly influenced the observed degradation rate constant (kobs) values, with rate minima observed near pH 4.
(18) Alkylation of the N-terminal half resulted in biphasic calcium release with rates (kobs 153 s-1 and 10.9 s-1 respectively) similar to those observed in intact alkylated calmodulin.
(19) At 1.2 mM 2-BDB-TAMP, kobs = 0.060 min-1 and is not affected by alpha-ketoglutarate or GTP, but is decreased to 0.020 min-1 by 5 mM NADH and to zero by 5 mM ADP.
(20) A plot of the pseudo-first order rate constant (Kobs) versus T1K concentration was linear, and values for the association (k1) and dissociation (k-1) rate constants were obtained.