Abstract

The long-term objective is to study the functional properties of human hemoglobins that have been altered by mutation, chemical modification, or both in order to gain further insight into the molecular mechanisms involved in the binding and transport of oxygen by hemoglobin. The results will be used for two purposes. First, attempts will be made to correlate functional properties with structural alterations in order to better understand the contributions of specific amino acid residues in hemoglobin and changes in the molecule's tertiary and quaternary structures to its oxygen transport. Second, functional properties of chemically modified hemoglobins will be measured and analyzed in an attempt to identify and design cross-linking reagents that may be useful in producing hemoglobin-based substitutes for whole blood transfusion.
The specific aims i nclude: (1) The functional properties of chemically cross-linked normal and mutant hemoglobins will be measured and correlated in order to identify structural modifications that result in oxygen binding properties that are in a physiologically useful range when the modified hemoglobin is free in solution. (2) Functionally abnormal hemoglobins will be examined in detail to determine, as precisely as possible, which parts of the overall reaction with oxygen have been altered by the mutational change. (3) Previously unstudied and all new abnormal hemoglobins that can be obtained will be screened for their general parameters of oxygen binding in order to identify whether or not the altered residue influences normal oxygen binding. (4) Attempts will be made to correlate changes in oxygen equilibrium reaction with altered protein structure in order to better understand the normal reaction mechanism and the relation of the structure and function of this protein. The principal methods used will be the measurement of oxygen equilibrium reaction over its full range by the automatic recording method under various controlled conditions of pH, ions, and temperature.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL020142-18
Application #
2215318
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1977-01-01
Project End
1995-12-30
Budget Start
1994-07-01
Budget End
1995-12-30
Support Year
18
Fiscal Year
1994
Total Cost
Indirect Cost

  Institution

Name
Oregon Health and Science University
Department
Dentistry
Type
Schools of Dentistry
DUNS #
009584210
City
Portland
State
OR
Country
United States
Zip Code
97239

  Publications

Elder, G E; Lappin, T R; Horne, A B et al. (1998) Hemoglobin Old Dominion/Burton-upon-Trent, beta 143 (H21) His-->Tyr, codon 143 CAC-->TAC--a variant with altered oxygen affinity that compromises measurement of glycated hemoglobin in diabetes mellitus: structure, function, and DNA sequence. Mayo Clin Proc 73:321-8
Schumacher, M A; Zheleznova, E E; Poundstone, K S et al. (1997) Allosteric intermediates indicate R2 is the liganded hemoglobin end state. Proc Natl Acad Sci U S A 94:7841-4
Merritt, D; Jones, R T; Head, C et al. (1997) Hb Seal Rock [(alpha 2)142 term-->Glu, codon 142 TAA-->GAA]: an extended alpha chain variant associated with anemia, microcytosis, and alpha-thalassemia-2 (-3.7 Kb). Hemoglobin 21:331-44
Hutt, P J; Donaldson, M H; Khatri, J et al. (1996) Hemoglobin S/hemoglobin Osler: a case with 3 beta globin chains. DNA sequence (AAT) proves that Hb Osler is beta 145 Tyr-->Asn. Am J Hematol 52:305-9
Jones, R T; Shih, D T; Fujita, T S et al. (1996) A doubly cross-linked human hemoglobin. Effects of cross-links between different subunits. J Biol Chem 271:675-80
Perutz, M F; Shih, D T; Williamson, D (1994) The chloride effect in human haemoglobin. A new kind of allosteric mechanism. J Mol Biol 239:555-60
Stabler, S P; Jones, R T; Head, C et al. (1994) Hemoglobin Denver [alpha 2 beta 2(41) (C7) Phe-->Ser]: a low-O2-affinity variant associated with chronic cyanosis and anemia. Mayo Clin Proc 69:237-43
Kluger, R; Jones, R T; Shih, D T (1994) Cross-linking hemoglobin by design: lessons from using molecular clamps. Artif Cells Blood Substit Immobil Biotechnol 22:415-28
Jones, R T (1994) Structural characterization of modified hemoglobins. Methods Enzymol 231:322-43
Krishnan, K; Martinez, F; Wille, R T et al. (1994) Hb Washtenaw [ beta 11(A8)Val-->Phe]: an electrophorectically silent, unstable, low oxygen affinity variant associated with anemia and chronic cyanosis. Hemoglobin 18:285-95

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