Biochemical Nomenclature Committees

The International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Biochemistry and Molecular Biology (IUBMB) have established the IUPAC-IUBMB Joint Commission on Biochemical Nomenclature (JCBN) and the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB). A short outline on the purpose and aim of these Committees is outlined in the paragraphs below.

More detailed information and the recommendations for biochemical nomenclature including enzyme nomenclature can be found on the nomenclature website and on a website with sophisticated search function that is dedicated to enzyme nomenclature. JCBN Newsletters can be found at JCBN Newsletters

Purpose of the Committees

The purpose of the committees is to facilitate communication of biochemical information by encouraging scientists to use generally understood terminology.

They make recommendations with this aim. The committees seek advice from experts in the diverse fields of biochemistry about matters where communication is difficult because of inconsistent practices. This is the starting point of most of the initiatives of the committees. The experts consulted include journal editors and database managers. For example, the recommendations for a Nomenclature for Incompletely Specified Bases in Nucleic Acid Sequences (1984) arose out of an attempt by an international group of experts to resolve the confusion that previously resulted from the existence of many different systems to represent combinations such as “G or C”, which had been written in at least five different ways.


The present nomenclature committees were created by the International Union of Biochemistry (IUB; now the International Union of Biochemistry and Molecular Biology, IUBMB) and the International Union of Pure and Applied Chemistry (IUPAC) to replace the IUPAC-IUB Commission on Biochemical Nomenclature (CBN), which was discontinued in 1977. Formally there are two committees:

  • JCBN, the IUPAC-IUBMB Joint Commission on Biochemical Nomenclature
  • NC-IUBMB, the Nomenclature Committee of IUBMB

with somewhat different terms of reference. JCBN is jointly responsible to both International Unions, and deals with matters of biochemical nomenclature that have importance in both biochemistry and chemistry. NC-IUBMB is responsible only to IUBMB and deals with matters of biochemical nomenclature that are more remote from the interests of chemists.

In practice there is considerable overlap in the tasks of the two committees and they always work and meet as a single body, with a common Chairman and a common Secretary. The present members are listed on the web. Unless otherwise indicated, therefore, the term “nomenclature committees” in this page refers equally to JCBN and to NC-IUBMB.

Procedures for Establishing New Recommendations

The initial recommendations for any topic are always prepared by experts in the subject area, but are subsequently studied by the nomenclature committees in an effort to harmonize them with recommendations in related areas of biochemistry, or indeed in chemistry and other disciplines. Although this step often appears unnecessary to experts in a restricted area of the subject, its importance emerges when one attempts to present information on a broader scale or to a broader audience. As an example, some years ago the nomenclature committees were asked to advise on some draft recommendations in which I (in ordinary roman type and without any qualifiers) was proposed as a standard symbol that could be used without definition for a particular immunoglobulin; they had to point out that this could only be acceptable in a very narrow context, as it would be confusing whenever the chemical symbol for iodine might be needed, or if the one-letter code for isoleucine and the symbol for ionic strength were also used (quite apart from confusion with the personal pronoun, as, for example, in “I mixed I with 131I-labelled thyroxine in a solution of I = 0.5 mol/l containing 5mM”). Further review is required after the nomenclature committees are satisfied with any recommendations, as the International Unions, which have ultimate responsibility for any publication, need to be satisfied that they represent the views of a broad range of experts. The actual review procedures of the two Unions differ somewhat, but their aims are the same, and they also have the additional consequence that preparing any document is inevitably slow. Even the most rapidly produced documents, such as the Nomenclature for Incompletely Specified Bases in Nucleic Acid Sequences noted above, which encountered no serious obstacles on the way to approval, typically take at least two years.

Connections with Other Bodies

There is inevitably some overlap between the work of the biochemical nomenclature committees and similar bodies in other disciplines, especially through IUPAC Division VIII, Chemical Nomenclature and Structure Representation. Many IUPAC nomenclature recommendations are available through the web. To avoid arriving at conflicting recommendations the nomenclature committees maintain close relations with such bodies (and during the existence of the present committees they have always included present or former members of CNOC among their members). Input from other committees concerned with biochemical nomenclature is always welcomed, and any such body interested in sending an Observer to meetings of JCBN and NC-IUBMB is invited to contact the Secretary, Dr. S Boyce.

Publication of Recommendations

Apart from Enzyme Nomenclature, discussed below, recommendations of the nomenclature committees are published in the primary research literature. All JCBN recommendations are published in Pure and Applied Chemistry, and all JCBN and NC-IUBMB recommendations are currently published in the FEBS Journal, formerly known as the European Journal of Biochemistry, by courtesy of FEBS. Many documents appear also in other journals, and any journal wishing to republish a document can normally obtain reproduction-quality proofs from the FEBS Journal, to avoid the need for re-setting. However, it is not obligatory to use these proofs, and journals that prefer to set the type themselves may do so without any copyright complications. From time to time these documents are published together as a Compendium, Biochemical Nomenclature and Related Documents; the most recent edition was published by Portland Press for IUBMB in 1992 (ISBN 1 85578 005 4).

A list of JCBN and NC-IUBMB publications is available through the web, and the full texts of the following are also there. Others will be added as time permits.