The irreversible thermal inactivation and the thermodynamics of calcium ion binding of Bacillus amyloliquefaciens alpha-amylase in the absence of substrates were studied. The enzyme inactivation on heating was apparently followed by first-order kinetics. The enzyme was stabilized with an increased concentration of calcium ion and thus the inactivation was highly dependent on the state of calciu...

The binding of adenosine 5'-monophosphate to liver glycogen phosphorylase a (EC 2.4.1.1) has been studied by size exclusion high performance liquid chromatography and isothermal titration microcalorimetry at pH 6.9 over a temperature range of 25 to 35 degrees C. The results are compared with those of the binding of the same nucleotide to the muscle isozyme and to liver phosphorylase b. Calorime...

A basic lectin (pI approximately 10.0) was purified to homogeneity from the seeds of winged bean (Psophocarpus tetragonolobus) by affinity chromatography on Sepharose 6-aminocaproyl-D-galactosamine. The lectin agglutinated trypsinized rabbit erythrocytes and had a relative molecular mass of 58,000 consisting of two subunits of Mr 29,000. The lectin binds to N-dansylgalactosamine, leading to a 1...

Binding parameters of the N-phenyl benzene sulfonyl hydrazide, sulfonamide, and nanosulfonamide interaction with Human serum albumin were determined by calorimetry method. The obtained binding parameters indicated that sulfonamide in the second binding sites has higher affinity for binding than the first binding sites. The binding process of sulfonamide to HSA is both enthalpy and entropy drive...

BACKGROUND Interaction of the iminium and alkanolamine forms of sanguinarine with bovine serum albumin (BSA) was characterized by spectroscopic and calorimetric techniques. METHODOLOGY/PRINCIPAL FINDINGS Formation of strong complexes of BSA with both iminium and alkanolamine forms was revealed from fluorescence quenching of sanguinarine. Binding parameters calculated from Stern-Volmer quenchi...

a palladium composite membrane was prepared by electroless plating on oxidized porous stainless steel support (ox-pss). hydrogen permeation flux through this composite membrane was measured in the temperature range of 574-674k and the pressure difference of two sides of membrane up to 90kpa. a simplified resistance model was employed to analyze the permeation behavior of hydrogen through pd/ox-...

Many flavoproteins are non-covalent complexes between FMN and an apoprotein. To understand better the stability of flavoproteins, we have studied the energetics of the complex between FMN and the apoflavodoxin from Anabaena PCC 7119 by a combination of site-directed mutagenesis, titration calorimetry, equilibrium binding constant determinations, and x-ray crystallography. Comparison of the stre...

The molecular structures and enthalpy release of poly(amidoamine) (PAMAM) dendrimers binding to 1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC) bilayers were explored through atomistic molecular dynamics. Three PAMAM dendrimer terminations were examined: protonated primary amine, neutral acetamide, and deprotonated carboxylic acid. Fluid and gel lipid phases were examined to extract the eff...

background: heat stress evaluation and timely notification, especially using meteorological data is an important issue attracted attention in recent years. therefore, this study aimed at answering the following research questions: 1) can enthalpy as a common environmental parameter reported by meteorological agencies be applied accurately for evaluation of thermal condition of outdoor settings,...