Biomaterial Database

Circular dichroism studies of the binding of o-nitrophenyl-beta-D-fucoside and o-nitrophenyl-beta-D-galactoside to lac repressor. 1977

J C Maurizot, and M Charlier

The binding of o-nitrophenyl-beta-D-fucoside and o-nitrophenyl-beta-D-galactoside to Escherichia coli lac repressor was investigated by circular dichroism in the wavelength range 300--400 nm corresponding to the o-nitrophenyl chromophores. The CD signal of both ligands drastically changed when they bound to lac repressor due to the asymmetric interaction of the o-nitrophenyl ring with chemical groups of protein. The CD spectra of bound ligands indicate close similarity between the environment of o-nitrophenyl-beta-D-fucoside and o-nitrophenyl-beta-D-galactoside on lac repressor. The CD signal is used to calculate the binding parameters (K and n) to lac repressor. It is demonstrated that the limited proteolytic digestion of lac repressor which gives a 'core protein' does not affect the environment of both ligands on the protein.

UI	MeSH Term	Description	Entries
D007785	Lactose	A disaccharide of GLUCOSE and GALACTOSE in human and cow milk. It is used in pharmacy for tablets, in medicine as a nutrient, and in industry.	Anhydrous Lactose,Lactose, Anhydrous
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D008968	Molecular Conformation	The characteristic three-dimensional shape of a molecule.	Molecular Configuration,3D Molecular Structure,Configuration, Molecular,Molecular Structure, Three Dimensional,Three Dimensional Molecular Structure,3D Molecular Structures,Configurations, Molecular,Conformation, Molecular,Conformations, Molecular,Molecular Configurations,Molecular Conformations,Molecular Structure, 3D,Molecular Structures, 3D,Structure, 3D Molecular,Structures, 3D Molecular
D009598	Nitrophenylgalactosides	Includes ortho-, meta-, and para-nitrophenylgalactosides.	Nitrophenylgalactopyranosides
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D004794	Enzyme Repression	The interference in synthesis of an enzyme due to the elevated level of an effector substance, usually a metabolite, whose presence would cause depression of the gene responsible for enzyme synthesis.	Repression, Enzyme
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005643	Fucose	A six-member ring deoxysugar with the chemical formula C6H12O5. It lacks a hydroxyl group on the carbon at position 6 of the molecule.	Deoxygalactose,alpha-Fucose,alpha Fucose
D006027	Glycosides	Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)	Glycoside