Alamethicin: A Peptide Model for Voltage Gating and Protein-Membrane Interactions

CONTENTS PERSPECTIVES AND OVERVIEW 1 41 ENERGETIC REQUIREMENTS FOR ION TRANSPORT. . . . . . . . . . . . . . . . . . 1 43 GENERAL FEATURES AND SEQUENCE OF ALAMETHICIN . ... .... ... 1 45 CHANNEL ACTIVITY OF ALAMETHlCIN ... . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 46 Macroscopic Conductances in Planar Bilayers ........ 1 46 Single Channel Conductance Measurements ... ...... . .... ....... . ..... . 1 47 Conductance Measurements in Vesicles . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 147 The Activity of Alamethicin Analogues ....... 1 49 STRUCTURE AND DYNAMICS OF ALAMETHICIN . . . . . . . . . . . . . . . . . . . . . 150 Crystal Structure ... ....... ... 150 Structure Derived from Spectroscopic Studies 1 52 Membrane Binding and Aggregation of Alamethicin . .. . .. . .. ....... . .. .. 154 MODELS FOR THE ALAMETHICIN CHANNEL .. 156 Structure of the Ion Channel . . . 156 Models for Voltage-Dependent Gating .. , . . . . . . . . . . . . : . . . . . . . . . . . . . . . . . . 1 57 Additional Mechanisms and Structural Considerations .. . . .. . . 1 60 FUTURE DIRECTIONS 161