Cooperative interactions of hemoglobin.

INTRODUCTION ............................................................. 209 FORMULATIONS Ot v THE PROBLEM OF COOPERATIVE LIGAND B1NDING ...... 210 Earl), Models ................................................................... 210 The Adair Scheme .............................................................. 211 The Sequential Models .......................................................... 211 The Two-State Model ........................................................... 213 THE MINIMUM UNIT OF COOPERATIVITY ....................................... 216 DEDUCTIONS EROM STRUCTURAL STUDIES .................................... 219 DETECTION OF THE T~-~R TRANSITION ......................................... 221 EVIDENCE FOR NONEQUIVALENCE OF THE ~ AND /~ CHAINS .................. 223 Basic Observations ............................................................... 223 Consequences ~f Chain Nonequivalence ............................................... 225 GENERAL CONCLUSIONS AND’CURRENT ISSUES ............................... 226