Actin and Tubulin Polymerization: The Use of Kinetic Methods to Determine Mechanism

CONTENTS PERSPECTIVES AND SUMMARy 189 GENERAL PROPERTIES OF THE POLYMERIZING UNIT 190 Actin 190 Tubulin 191 ASSAY METHODS FOR THE POLYMERIZATION PROCESS 192 Actin 192 Tubulin 193 THE SIMPLE MODEL FOR ACTIN AND TUBULIN POLYMERIZATION 194 Kinetic Theory 195 Experimental Results 197 Fragmentation and Reannealing 200 THE MECHANISM OF ELONGATION 201 POLARITY .. 202 THE CRITICAL CONCENTRATION 204 THE ROLE OF NUCLEOSIDE 0\AND TRIPHOSPHATE 205 THE ROLE OF NUCLEOTIDE HYDROL YSIS 207