Oxygen infrared spectra of oxyhemoglobins and oxymyoglobins. Evidence of two major liganded O/sub 2/ structures
The dioxygen stretch bands in infrared spectra for solutions of oxy species of human hemoglobin A and its separated subunits, human mutant hemoglobin Zurich (..beta..63His to Arg), rabbit hemoglobin, lamprey, hemoglobin, sperm whale myoglobin, bovine myoglobin, and a sea worm chlorocruorin are examined. Each protein exhibits multiple isotope-sensitive bands between 1160 and 1060 cm/sup -1/ for the liganded /sup 16/O/sub 2/, /sup 17/O/sub 2/, and /sup 18/O/sub 2/. The O-O stretch bands for each of the mammalian myoglobins and hemoglobins are similar, with frequencies that differ between proteins by only 3-5 cm/sup -1/. The spectra for the lamprey and sea worm hemoglobins exhibit greater diversity. For all proteins an O-O stretch band expected to occur near 1125 cm/sup -1/ for /sup 16/O/sub 2/ and /sup 17/O/sub 2/, but not /sup 18/O/sub 2/, appears split by approx.25 cm/sup -1/ due to an unidentified perturbation. The spectrum for each dioxygen isotope, if unperturbed, would contain two strong bands for the mammalian myoglobins (1150 and 1120 cm/sup -1/) and hemoglobins (1155 and 1125 cm/sup -1/). Two strong bands separated by approx.30 cm/sup -1/ for each oxy heme protein subunit indicate that two major protein conformations (structure) that differ substantially in O/sub 2/ bonding are present. The two dioxygen structures can result from a combination of dynamic distal and proximal effects upon the O/sub 2/ ligand bound in a bent-end-on stereochemistry.
- Research Organization:
- Colorado State Univ., Fort Collins
- OSTI ID:
- 5943038
- Journal Information:
- Biochemistry; (United States), Vol. 26:15
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HEMOGLOBIN
INFRARED SPECTRA
LABELLED COMPOUNDS
MYOGLOBIN
CATTLE
INVERTEBRATES
LIGANDS
MAN
OXYGEN 16
OXYGEN 17
OXYGEN 18
RABBITS
STEREOCHEMISTRY
ANIMALS
CARBOXYLIC ACIDS
DOMESTIC ANIMALS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GLOBIN
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MAMMALS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN ISOTOPES
PIGMENTS
PORPHYRINS
PRIMATES
PROTEINS
RUMINANTS
SPECTRA
STABLE ISOTOPES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques