Hemoglobin conformation couples erythrocyte S-nitrosothiol content to O2 gradients.

ABSTRACT: It is proposed that the bond between nitric oxide (NO) and the Hb thiol Cys-beta(93) (SNOHb) is favored when hemoglobin (Hb) is in the relaxed (R, oxygenated) conformation, and that deoxygenation to tense (T) state destabilizes the SNOHb bond, allowing transfer of NO from Hb to form other (vasoactive) S-nitrosothiols (SNOs). However, it has not previously been possible to measure SNOHb without extensive Hb preparation, altering its allostery and SNO distribution. Here, we have validated an assay for SNOHb that uses carbon monoxide (CO) and cuprous chloride (CuCl)-saturated Cys. This assay is specific for SNOs and sensitive to 2-5 pmol. Uniquely, it measures the total SNO content of unmodified erythrocytes (RBCs) (SNO(RBC)), preserving Hb allostery. In room air, the ratio of SNO(RBC) to Hb

SUBMITTER: Doctor A 

PROVIDER: S-EPMC556285 | biostudies-literature | 2005 Apr

REPOSITORIES: biostudies-literature