Permeability characteristics of erythrocyte ghosts prepared under isoionic conditions by a glycol-induced osmotic lysis

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

External organisations

  • Birmingham University
  • Department of Biochemistry

Abstract

A detailed study has been made of the permeability characteristics of human erythrocyte ghosts prepared under isoionic conditions by a glycol-induced lysis (Billah, M.M., Finean, J.B., Coleman, R. and Michell, R.H. (1976) Biochim. Biophys. Acta 433, 45-54). Impermeability to large molecules such as dextran (average molecular weight 70 000) was restored immediately and spontaneously after each of the 5-7 lyses that were required to remove all of the haemoglobin. Permeabilities to smaller molecules such as MgATP2-, [3H]inositol and [14C]choline were initially high but could be greatly reduced by incubation at 37°C for an hour. The extent of such resealing decreased as the number of lyses to which the ghosts had been subjected increased. Both removal of haemoglobin and permeabilities to small molecules were affected significantly by pH, Ca2+ concentrations and divalent cation chelators. Maximum resealing was achieved in ghosts prepared in the basic ionic medium (130 mM KCl, 10 mM NaCl, 2 mM MgCl2, 10 mM N-2-hydroxyethylpiperazine-N′-2-ethanesulphonic acid (HEPES)) at pH 7.0 (0°C) and with a calcium level around 10-5 M. Acidic pH facilitated the removal of haemoglobin whilst the presence of divalent cation chelators slowed down its release. Retention of K+ by ghosts loaded with K+ during the first lysis and subsequently incubated at 37° C was substantial but little K+ could be retained within the haemoglobin-free ghosts. Permeability of the ghosts to K+ after one lysis was affected by temperature, pH, Ca2+ concentrations and by the presence of divalent cation chelators.

Details

Original languageEnglish
Pages (from-to)515-526
Number of pages12
JournalBBA - Biomembranes
Volume465
Issue number3
Publication statusPublished - 17 Mar 1977