APPENDIX 1A Enzyme Nomenclature

Published Online: 1 MAY 2001

DOI: 10.1002/0471141755.pha01as00

Current Protocols in Pharmacology

Current Protocols in Pharmacology

How to Cite

2001. Enzyme Nomenclature. Current Protocols in Pharmacology. 00:1A:A.1A.1–A.1A.3.

Publication History

  1. Published Online: 1 MAY 2001
  2. Published Print: MAR 1998


This appendix describes the “EC” (Enzyme Commission) numbering convention, starting with how enzymes are first grouped into one of six classes according to the reaction catalyzed, and then subclassified in terms of the donors, then acceptors, and then the actual enzyme reaction. An example is given of the major sub-subclasses of oxidoreductases along with many hundreds of enzymes in this class. Because this classification procedure came into being when there was little knowledge of enzyme structure and when protein cloning and expression was in its infancy, enzymes are classified according to their function. This is unlike receptor classification, which relies on structure and coupling.