Regulation of linkages between the erythrocyte membrane and its skeleton by 2,3-diphosphoglycerate

• Published in: The Journal of biological chemistry Vol. 268; no. 15; pp. 10990 - 10996
• Main Authors: Moriyama, R., Lombardo, C.R., Workman, R.F., Low, P.S.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 25.05.1993; American Society for Biochemistry and Molecular Biology
• Subjects: 2,3-Diphosphoglycerate; Ankyrins - isolation & purification; Ankyrins - metabolism; Biological and medical sciences; Calorimetry, Differential Scanning; Cell structures and functions; Cytoskeletal Proteins; Cytoskeleton, cytoplasm. Intracellular movements; Diphosphoglyceric Acids - pharmacology; Erythrocyte Membrane - drug effects; Erythrocyte Membrane - metabolism; Fundamental and applied biological sciences. Psychology; Humans; Kinetics; Membrane Proteins - isolation & purification; Membrane Proteins - metabolism; Molecular and cellular biology; Neuropeptides; Protein Binding; Human; Differential scanning calorimetry; 2,3-Diphosphoglycerate; Plasma membrane; Red blood cell; Cytoskeleton; Molecular interaction
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)82083-X

In addition to reducing hemoglobin-O2 affinity, 2,3-diphosphoglycerate (DPG) is known to modulate the mechanical properties of the erythrocyte membrane. By fluorescence spectroscopy and differential scanning calorimetry, we demonstrate that DPG binds the cytoplasmic domain of erythrocyte membrane band 3 in two stages characterized by apparent KD values of approximately approximately 2 and 12 mM. DPG was also shown to perturb the stability of ankyrin, protein 4.1, and protein 4.2 in situ and to directly bind to protein 4.1. In studies of membrane-skeleton interactions, DPG was observed to inhibit the fast and slow phases of ankyrin binding to band 3 and to reduce both the number of ankyrin sites and affinity of ankyrin for each class of site. The inhibition was biphasic, similar to the band 3-DPG binding isotherm; however, at physiological DPG concentrations a reduction in only 15% of the ankyrin sites was observed. In contrast, inhibition of protein 4.1 binding to the membrane reached 65% at physiological DPG concentrations (approximately approximately 5.9 mM); at more elevated concentrations, blockade was nearly quantitative, affecting glycophorin and band 3 sites alike. Taken together with previous observations, these data suggest that DPG's effect on O2 delivery may extend beyond its well recognized impact on hemoglobin-O2 affinity.