Biomaterial Database

Methemoglobin formation and reduction in relation to hemoglobin oxygen affinity. 1981

A Mansouri

It is suggested that although the high oxygen affinity hemoglobins (Hb LR) (beta 143(H21)His leads to Gln) with stabilization of R quaternary conformation is not more susceptible to the oxidizing effect of nitrites in vitro, in an in vivo situation where hemoglobin is partly deoxygenated, it might be more susceptible to methemoglobin formation due to higher oxidation and lower reduction rate.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008706	Methemoglobin		Ferrihemoglobin
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
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
D006441	Hemoglobin A	Normal adult human hemoglobin. The globin moiety consists of two alpha and two beta chains.
D006455	Hemoglobins, Abnormal	Hemoglobins characterized by structural alterations within the molecule. The alteration can be either absence, addition or substitution of one or more amino acids in the globin part of the molecule at selected positions in the polypeptide chains.	Abnormal Hemoglobins
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012977	Sodium Nitrite	Nitrous acid sodium salt. Used in many industrial processes, in meat curing, coloring, and preserving, and as a reagent in ANALYTICAL CHEMISTRY TECHNIQUES. It is used therapeutically as an antidote in cyanide poisoning. The compound is toxic and mutagenic and will react in vivo with secondary or tertiary amines thereby producing highly carcinogenic nitrosamines.	Nitrite, Sodium
D042966	Cytochrome-B(5) Reductase	A FLAVOPROTEIN oxidoreductase that occurs both as a soluble enzyme and a membrane-bound enzyme due to ALTERNATIVE SPLICING of a single mRNA. The soluble form is present mainly in ERYTHROCYTES and is involved in the reduction of METHEMOGLOBIN. The membrane-bound form of the enzyme is found primarily in the ENDOPLASMIC RETICULUM and outer mitochondrial membrane, where it participates in the desaturation of FATTY ACIDS; CHOLESTEROL biosynthesis and drug metabolism. A deficiency in the enzyme can result in METHEMOGLOBINEMIA.	Methemoglobin Reductase,NADH Cytochrome B5 Reductase,NADH Methemoglobin Reductase,NADH-Cytochrome B5 Reductase,NADH-Ferrihemoglobin Reductase,B5 Reductase, NADH-Cytochrome,Methemoglobin Reductase, NADH,NADH Ferrihemoglobin Reductase,Reductase, Methemoglobin,Reductase, NADH Methemoglobin,Reductase, NADH-Ferrihemoglobin