Biomaterial Database

Spin relaxation of iron in mixed state hemoproteins. 1986

E Wajnberg, and H J Kalinowski, and G Bemski, and J S Helman

In hemoproteins the relaxation mechanism of iron is Orbach for high spin (HS) and Raman for low spin (LS). We found that in met-hemoglobin and met-myoglobin, under conditions in which the two spin states coexist, both the HS and the LS states relax to the lattice through Orbach-like processes. Alos, very short (approximately 1 ns) and temperature independent transverse relaxation times T2 were estimated. This may result from the unusual electronic structure of mixed states hemoproteins that allows thermal equilibrium and interconversion of the spin states.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
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.
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
D004578	Electron Spin Resonance Spectroscopy	A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.	ENDOR,Electron Nuclear Double Resonance,Electron Paramagnetic Resonance,Paramagnetic Resonance,Electron Spin Resonance,Paramagnetic Resonance, Electron,Resonance, Electron Paramagnetic,Resonance, Electron Spin,Resonance, Paramagnetic
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
D006736	Horses	Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.	Equus caballus,Equus przewalskii,Horse, Domestic,Domestic Horse,Domestic Horses,Horse,Horses, Domestic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013059	Spectrum Analysis, Raman	Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light.	Raman Spectroscopy,Analysis, Raman Spectrum,Raman Optical Activity Spectroscopy,Raman Scattering,Raman Spectrum Analysis,Scattering, Raman,Spectroscopy, Raman
D014907	Whales	Large marine mammals of the order CETACEA. In the past, they were commercially valued for whale oil, for their flesh as human food and in ANIMAL FEED and FERTILIZERS, and for baleen. Today, there is a moratorium on most commercial whaling, as all species are either listed as endangered or threatened.	Beaked Whales,Berardius,Caperea,Dwarf Sperm Whale,Giant Bottle-Nosed Whales,Goose-Beaked Whale,Gray Whale,Mesoplodon,Narwhals,Pygmy Right Whale,Pygmy Sperm Whale,Right Whale, North Atlantic,Right Whale, Southern,Ziphiidae,Ziphius,Eschrichtius robustus,Eubalaena australis,Grey Whale,Monodon monoceros,North Atlantic Right Whale,Beaked Whale,Bottle-Nosed Whale, Giant,Bottle-Nosed Whales, Giant,Dwarf Sperm Whales,Giant Bottle Nosed Whales,Giant Bottle-Nosed Whale,Goose Beaked Whale,Goose-Beaked Whales,Gray Whales,Grey Whales,Narwhal,Pygmy Right Whales,Pygmy Sperm Whales,Right Whale, Pygmy,Right Whales, Pygmy,Right Whales, Southern,Southern Right Whale,Southern Right Whales,Sperm Whale, Dwarf,Sperm Whale, Pygmy,Sperm Whales, Dwarf,Sperm Whales, Pygmy,Whale,Whale, Grey,Whale, Southern Right,Whales, Grey,Whales, Southern Right