Hot atom labeling of myoglobin and hemoglobin and biophysical studies of oxygen and CO binding to carp hemoglobin
Human Hb, the monomeric Hb of Glycera dibranchiata and horse Mb were modified by replacement of the protoheme with 2,4-dibromodeuteroheme. Following neutron capture by [sup 79]Br and [sup 81]Br, the locations of radioactive Br were determined. Although human Hb had approximately four times the mass and volume of the other proteins, about 9% of the activated Br was inserted into each of the three globins. These results suggest that the insertion is short-range (within 15 [angstrom]) and that this method could be used to label target sites in various proteins and other biological structures. Carp Hb's containing proto-, meso-, deutero- and dibromoheme were prepared. Kinetic and thermodynamic parameters for oxygen and CO binding were determined at Ph 6 (+IHP) (T-state, low-affinity protein) and Ph 9 (R-state, high-affinity protein). Parameters for the binding of oxygen and CO were related to the properties of the four hemes to estimate the inductive and steric factors in the ligation process. The results suggest that the steric factors are more important for the T-state than for the R-state. The T-state carp Hbs were very readily oxidized. Two new procedures were developed for the rapid determination of oxygen equilibrium isotherms for the T-state carp Hbs. The kinetic and thermodynamic parameters for ligation of oxygen and CO with the isolated carp [alpha]-chains were determined. Carp [alpha]-chains are the only hemoglobin chains isolated to date that can be classified as T-state. The secondary thermodynamic parameter ([delta]H[degrees]) was found to be essential for classifying hemoglobins as T- or R-state.
- Research Organization:
- Nebraska Univ., Lincoln, NE (United States)
- OSTI ID:
- 7165642
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BROMINE 79
CAPTURE
NEUTRON REACTIONS
BROMINE 81
HEMOGLOBIN
LABELLING
MYOGLOBIN
BARYON REACTIONS
BROMINE ISOTOPES
CARBOXYLIC ACIDS
GLOBINS
HADRON REACTIONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PIGMENTS
PORPHYRINS
PROTEINS
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
STABLE ISOTOPES
400703* - Radiochemistry & Nuclear Chemistry- Radioisotope Production