The binding behavior of a competitive inhibitor, N-phenylbenzhydroxamic acid (BHA) against horseradish peroxidase (HRP) was studied in order to understand and predict the interaction mechanism of hydrogen donors with the enzyme. The dissociation constants of the complexes of HRP-BHA, HRP-donor and HRP-BHA-azide were estimated at specified conditions by difference spectroscopy. The binding s...

The synthesis of N-acetyl-L-isoasparagine and of N-acetylL-isoglutamine is reported. The acid dissociation constants of these compounds, and those of their corresponding Ncarbobenzoxy derivatives, have been measured. Since these compounds are uncharged molecules of the type -NH-CH(-CH,COOH)-COor the corresponding glutamyl homologue, their dissociation constants represent the intrinsic dissociat...

The equilibrium constant of the phosphoglyceromutase reaction was determined over a range of pH (5.4-7.9), in solutions of different ionic strength (0.06-0.3) and in the presence of Mg(2+), at 30 degrees C and at 20 degrees C. The values obtained (8.65-11.65) differ substantially from previously published values. The third acid dissociation constants were redetermined for 2- and 3-phosphoglycer...

In this paper the apparent dissociation constants of arginine and of lysine at 25” and the apparent dissociation constants of arginine, lysine, histidine, aspartic acid, and glutamic acid at 0” are reported. We have made use of these data together with previously published data for the apparent dissociation constants of histidine, aspartic acid, and glutamic acid for the purpose of calculating ...

the binding behavior of a competitive inhibitor, n-phenylbenzhydroxamic acid (bha) against horseradish peroxidase (hrp) was studied in order to understand and predict the interaction mechanism of hydrogen donors with the enzyme. the dissociation constants of the complexes of hrp-bha, hrp-donor and hrp-bha-azide were estimated at specified conditions by difference spectroscopy. the binding site ...

The acid dissociation constant is an important physicochemical parameter of a substance, and knowledge of it is of fundamental importance in a wide range of applications and research areas. We present a critical review of published methods and approaches for the determination of acid dissociation constants, with a special emphasis on the pKa values of active pharmaceutical ingredients. a 2007 E...

A multiwavelength spectrophotometric approach has been developed to determine acid dissociation constants (pKa values) of sparingly soluble drug compounds. UV absorption spectra of the drug solution are acquired using a versatile device based on a fiber optics dip probe, a light source and a photodiode array (PDA) detector while the PH and the ionic strength of the chemical system is manipulate...