Skip to main content
Article
Ligand binding to heme proteins: relevance of low-temperature data
Biochemistry (1986)
  • Todd B. Sauke, San Jose State University
  • Anjum Ansari, University of Illinois at Urbana-Champaign
  • Ernesto E. Dilorio, University of Illinois at Urbana-Champaign
  • Dana D. Dlott, University of Illinois at Urbana-Champaign
  • Hans Frauenfelder, University of Illinois at Urbana-Champaign
  • Icko T. Iben, University of Illinois at Urbana-Champaign
  • Peter Langer, University of Illinois at Urbana-Champaign
  • Heinrich Roder, University of Illinois at Urbana-Champaign
  • Erramilli Shyamsunder, University of Illinois at Urbana-Champaign
Abstract
Binding of carbon monoxide to the B chain of adult human hemoglobin has been studied by flash photolysis over the time range from about 100 ps to seconds and the temperature range from 40 to 300 K. Below about 180 K, binding occurs directly from the pocket (process I) and is non-exponential in time. Above about 180 K, some carbon monoxide molecules escape from the pocket into the protein matrix. Above about 240 K, escape into the solvent becomes measurable. Process I can be observed up to 300 K. The low-temperature data extrapolate smoothly to 300 K, proving that the results obtained below 180 K provide functionally relevant information. The experiments show again that the binding process even at physiological temperatures is regulated by the final binding step at the heme iron and that measurements at high temperatures are not sufficient to fully understand the association process.
Publication Date
June, 1986
Publisher Statement
SJSU users: use the following link to login and access the article via SJSU databases
Citation Information
Todd B. Sauke, Anjum Ansari, Ernesto E. Dilorio, Dana D. Dlott, et al.. "Ligand binding to heme proteins: relevance of low-temperature data" Biochemistry Vol. 25 Iss. 11 (1986)
Available at: http://works.bepress.com/todd_sauke/10/