Abstract
Nitrite reductase activity of deoxyhemoglobin (HbA) in the red blood cell has been proposed as a non-nitric-oxide synthase source of deliverable nitric oxide (NO) within the vasculature. An essential element in this scheme is the dependence of this reaction on the quaternary/tertiary structure of HbA. In the present work sol-gel encapsulation is used to trap and stabilize deoxy-HbA in either the T or R quaternary state, thus allowing for the clear-cut monitoring of nitrite reductase activity as a function of quaternary state with and without effectors. The results indicate that reaction is not only R-T-dependent but also heterotropic effector-dependent within a given quaternary state. The use of the maximum entropy method to analyze carbon monoxide (CO) recombination kinetics from fully and partially liganded sol-gel-encapsulated T-state species provides a framework for understanding effector modulation of T-state reactivity by influencing the distribution of high and low reactivity T-state conformations.
Original language | English (US) |
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Pages (from-to) | 36874-36882 |
Number of pages | 9 |
Journal | Journal of Biological Chemistry |
Volume | 281 |
Issue number | 48 |
DOIs | |
State | Published - Dec 1 2006 |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology