Abstract: | The effects of chloramine-T, a reagent specific to methionine residues, on sodium channel gating mechanisms was investigated in neuroblastoma cell membrane. Treating the membrane with chloramine was found to retard inactivation kinetics and considerably reduce the slope of the inactivation curve, while pushing the activation curve toward hyperpolarization ranges without changing the slope of the central portion perceptibly. Effective activation charge, as determined from the limiting logarithmic slope of activation, was reduced by a factor of 1.17. Possible reasons for the changes observed in sodium channel gating mechanisms are discussed.Institute of Cytology, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 19, No. 6, pp. 789–795, November–December, 1987. |