Biomaterial Database

Sulfhydryl groups in hemoglobin. A new molecular probe at the alpha1 beta 1 interface studied by Fourier transform infrared spectroscopy. 1975

G H Bare, and J O Alben, and P A Bromberg

Infrared absorption bands due to sulfhydryl groups (VSH) of alpha-104(G11) and beta-112 (G14) cysteine residues of human carboxyhemoglobin (HbCO) have been observed near 2560 cm- minus 1 by use of Fourier transform infrared (FTIR) spectroscopy. The beta-93 cysteine SH groups absorb infrared radiation so weakly that they are not distinguished from background. Only single SH absorption bands due to the alpha-104 cysteines of pig and horse hemoglobin are observed. The SH absorption bands from human HbCO disappear in alkali, are broadened by detergent or guanidinium chloride, and show a complex titration curve, and an isotopic frequency shift (VSD/VSH equals to 0.7267) virtually identical with that reported for methanethiol. The integrated absorption coefficient (epsilonmM(area)) for 0.1 M ethanetiol increased with H-bond acceptor solvents in the order: CCl4 (0.07), water (0.21), acetone (0.43), and N,N-dimethyl-acetamide (1.35 mM- minus 1 cm- minus 2). Comparison of the integrated absorption coefficients for the alpha-104 cysteine SH (2.43), and the beta-112 SH (0.80), of human HbCO with those of ethanetiol solutions suggested specifically H-bonded structures with peptide carbonyl groups 4 (or 3) residues back in the G helices. This was found to agree with a molecular model of the alpha-chain G helix of horse HbO2 built to coordinates from M. F. Perutz.

UI	MeSH Term	Description	Entries
D008623	Mercaptoethanol	A water-soluble thiol derived from hydrogen sulfide and ethanol. It is used as a reducing agent for disulfide bonds and to protect sulfhydryl groups from oxidation.	2-ME,2-Mercaptoethanol,2 Mercaptoethanol
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D009211	Myoglobin	A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.
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
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011489	Protein Denaturation	Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.	Denaturation, Protein,Denaturations, Protein,Protein Denaturations
D002263	Carboxyhemoglobin		Carbomonoxyhemoglobin,Carbonmonoxyhemoglobin,Carbonylhemoglobin,Carboxyhemoglobin A,Carboxyhemoglobin C
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D005583	Fourier Analysis	Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)	Fourier Series,Fourier Transform,Analysis, Cyclic,Analysis, Fourier,Cyclic Analysis,Analyses, Cyclic,Cyclic Analyses,Series, Fourier,Transform, Fourier
D006454	Hemoglobins	The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.	Eryhem,Ferrous Hemoglobin,Hemoglobin,Hemoglobin, Ferrous