The secondary and tertiary structure of human plasma thyroxine-binding globulin (TBG) was investigated by circular dichroism and fluorescence properties. The relaxation time of TBG indicated that it is a compact, symmetric molecule. It was calculated from the far ultraviolet CD spectrum that about one-half of the peptide groups are equally distributed in alpha helical and beta structures. In th...

Conformational analysis of champedak galactose-binding (CGB) lectin under different urea concentrations was studied in phosphate-buffered saline (pH 7.2) using far-ultraviolet circular dichroism (far-UV CD), tryptophan (Trp) fluorescence and ANS fluorescence. In all cases, CGB lectin displayed a two-step, three-state transition. The first transition (from the native state to the intermediate st...

A novel β-cyclodextrin (β-CD) dimer was synthesized and surface-grafted by click chemistry onto azide-functionalized quartz surfaces in order to introduce the cooperative features of the β-CD dimer to solid surfaces. Using NMR and fluorescence spectroscopy, it is shown that the free β-CD dimer forms a 1:1 complex with the fluorescent guest molecule, 2-anilinonaphthalene-6-sulfonic acid (otherwi...

This article describes the use of optical spectroscopy in studying antibody-hapten interactions and in determining the equilibrium binding constants. Along with equilibrium binding data, spectroscopic tools often deliver structural information on binding-induced conformational changes of antibodies (or haptens). Structural implications of results from example antibody-hapten systems are include...

The absorption, circular dichroism, and fluorescence spectra have been measured on oxidized and reduced reaction center preparations from Rhodopseudomonas spheroides strain R-26 at 295 and 77” K. The spectra indicate that the 4 bacteriochlorophyll a and 2 bacteriopheophytin a molecules in the reaction center are contained in a single pigment complex. The absorption bands at 893, 804, and ‘760 i...

DNA condensing agents play a critical role in gene therapy. A tetranuclear nickel(II) complex, [Ni(II)(4)(L-2H)(H(2)O)(6)(CH(3)CH(2)OH)(2)]·6NO(3) (L=3,3',5,5'-tetrakis{[(2-hydroxyethyl)(pyridin-2-ylmethyl)amino]methyl}biphenyl-4,4'-diol), has been synthesized as a nonviral vector to induce DNA condensation. X-ray crystallographic data indicate that the complex crystallizes in the monoclinic sy...

7α- and 7β-hydroxysteroid dehydrogenases (HSDHs) are enzymes that can catalyze the isomerization of hydroxyl groups at site seven bile acids. In a previous study, we found activities 7β-HSDHs be inhibited by bilirubin. order to clarify impact, effects bilirubin on were studied kinetics, spectrum, docking analysis. The relative activity 7α-HSDH remained less than 40% under 1 mM bilirubin, only 1...

Thiopental (TPL) is a commonly used barbiturate anesthetic. Its binding with human serum albumin (HSA) was studied to explore the anesthetic-induced protein dysfunction. The basic binding interaction was studied by UV-absorption and fluorescence spectroscopy. An increase in the binding affinity (K) and in the number of binding sites (n) with the increasing albumin concentration was observed. Th...

Thiopental (TPL) is a commonly used barbiturate anesthetic. Its binding with human serum albumin (HSA) was studied to explore the anesthetic-induced protein dysfunction. The basic binding interaction was studied by UV-absorption and fluorescence spectroscopy. An increase in the binding affinity (K) and in the number of binding sites (n) with the increasing albumin concentration was observed. Th...

BACKGROUND Triptolide is a major active constituent isolated from Tripterygiumwilfordii Hook F, a Chinese herbal medicine. This study investigated the intermolecular interaction between triptolide and bovine serum albumin (BSA). MATERIALS AND METHODS The fluorescence, circular dichroism (CD) and molecular docking methods were used to investigate the intermolecular interaction between triptoli...