title: Effects of chemical modification of membrane thiol groups on hemolysis of human erythrocytes under hydrostatic pressure.
abstract: Membrane stability of the human erythrocyte under high pressure was examined by modifying membrane SH-groups with NEM or diamide. Hemolysis at 200 MPa of chemically modified erythrocytes was significantly suppressed by the prolonged incubation of them in a reagent-free medium above 30 degrees C prior to the application of high pressure. However, there was no detectable change regarding membrane phospholipid distribution, CD spectra and SDS-PAGE of membrane proteins, and intracellular K+ concentration during the incubation. On the other hand, the data of protein-spin labeling and SH-group content showed that the SH-groups buried in membrane proteins appeared on their surface by conformational changes of membrane proteins induced during the incubation. The extraction of peripheral proteins from NEM-treated membranes in 0.1 N NaOH was considerably suppressed by the incubation. These results suggest that, upon chemical modification of membrane SH-groups, protein-protein interactions are modulated during prolonged incubation above 30 degrees C so that high pressure-induced hemolysis is suppressed.
authors.affiliation: Department of Chemistry, Faculty of Science, Fukuoka University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Murata
authors.forename: J
authors.initials: J
authors.lastname: Kobayashi
authors.forename: E
authors.initials: E
authors.lastname: Kimoto
mesh_terms: D003958:Diamide / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000737:chemistry*; D005033:Ethylmaleimide / Q000494:pharmacology; D006461:Hemolysis; D006801:Humans; D006874:Hydrostatic Pressure; D008563:Membrane Lipids / Q000032:analysis; D008565:Membrane Proteins / Q000737:chemistry; D010743:Phospholipids / Q000032:analysis; D011487:Protein Conformation; D013438:Sulfhydryl Compounds / Q000502:physiology*
chemical_list: D008563:Membrane Lipids; D008565:Membrane Proteins; D010743:Phospholipids; D013438:Sulfhydryl Compounds; D003958:Diamide; D005033:Ethylmaleimide