The ENZYME database is a repository of enzyme nomenclature information, essential for metabolic database development. It contains data on 3705 enzymes and is accessible via the ExPASy WWW server. The database is based on IUBMB recommendations and includes EC numbers, enzyme names, catalytic activities, cofactors, and links to related protein sequences and families. It also links to human diseases associated with enzyme deficiencies. ENZYME is closely integrated with SWISS-PROT, allowing efficient updates and corrections between the two resources. The database is structured for both human and computer use, following SWISS-PROT and EMBL formats. Sample entries are provided, showing enzyme details and associated proteins. The current release (July 1999) requires 1.5 Mb of storage and includes user manuals, class descriptions, and retrieval instructions. ENZYME is released four times a year with no usage restrictions. Interactive access is available via ExPASy. An electronic version of the Biochemical Pathways Wallchart is provided, linking enzymes to ENZYME entries. ENZYME can be obtained via FTP. A form is available for submitting new data or updates to NC-IUBMB for EC number assignment. The database is regularly updated with new nomenclature information. References to relevant literature are provided.The ENZYME database is a repository of enzyme nomenclature information, essential for metabolic database development. It contains data on 3705 enzymes and is accessible via the ExPASy WWW server. The database is based on IUBMB recommendations and includes EC numbers, enzyme names, catalytic activities, cofactors, and links to related protein sequences and families. It also links to human diseases associated with enzyme deficiencies. ENZYME is closely integrated with SWISS-PROT, allowing efficient updates and corrections between the two resources. The database is structured for both human and computer use, following SWISS-PROT and EMBL formats. Sample entries are provided, showing enzyme details and associated proteins. The current release (July 1999) requires 1.5 Mb of storage and includes user manuals, class descriptions, and retrieval instructions. ENZYME is released four times a year with no usage restrictions. Interactive access is available via ExPASy. An electronic version of the Biochemical Pathways Wallchart is provided, linking enzymes to ENZYME entries. ENZYME can be obtained via FTP. A form is available for submitting new data or updates to NC-IUBMB for EC number assignment. The database is regularly updated with new nomenclature information. References to relevant literature are provided.