Report of the Commission on Enzymes of the International by itlpw9937


         Vol. 237, No. 4, April     1962
              Printed   in U.S.A.

                                                         EDITORIAL          COMMENT

         Report                     of the Commission   on Enzymes                              of the International
                                            Union of Biochemistry,                             1961
   This report has now been published by the Pergamon Press,               The II713 Commission of Editors has agreed that the code num-
and WE wish to call it to the attention of our rraders. The Com-           brrs of enzymes may be cited in papers by the letters EC pre-
mission on Enzymes was set up in 1955 by vote of the Intcr-                ceding the rode number; thus, the enzyme referred to above
national Trnion of Biochemistry,       and held its first meetings in      would be drnoted as EC
1956. It was charged with the responsibility         “To consider the         The Editorial    Officc of the Journal of Biological Chemistry
classification and nomcnclaturc of enzymes and cocnzymcs, their            has already received a large numbrr of comments on the report,
units of activity and standard methods of assay, togcthcr with             some of which have pointed out erroneous or inappropriate         de-
the symbols used in the description of enzyme kinetics.”                   scriptions of certain enzymes in tabulated list. The Editors
   The report that has now emerged, 159 printed pages in length,           will bc glad to receive further comments of this sort, and will
represents the result of prolonged and arduous work on the part            transmit them to Dr. E. C. Webb of Cambridge University, who
of the Commission and extensive correspondence with biochem-               is the Secretary of the present Standing Committee on Enzymes

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ists throughout   the world.    Following the introductory     chapter     of IU13. After a sufficient time has been allowed for the receipt
the topics considered are as follows:                                      of such criticisms, it will probably be necessary to set up a new
       Chapter 2. Enzyme Units                                             Commission on Enzymes to review the report and prepare a
       Chapter 3. Symbols of Enzymr Kinetics                               revised version.
       Chapter 4. The Nomenclature         of Cornzymts                        The Journal of Biological Chemistry does not insist that aut.hors
       Chapter 5. The Classification and Nomcncalaturc of Cyto-            should follow thr rccommendat.ions of the Enzyme Commission.
                    chromes                                                However, we urge the aut,hors of papers dealing with enzymes to
       Chapter 6. The Classification       and Nomcnclaturc     of En-     consider the report carefully and, when it seems appropriate,       to
                    zymrs                                                  rrfcr in parcnthrscs to the code number and systematic name of
       Chapter 7. The Terminology        of Enzymcx Formation              any enzyme that forms a major subject of the paper being sub-
       Chapter 8. General Conclusions                                      mitted.
       Chapter 9. Summary of Recommendations
These chapters arc followed by a series of apptxndices, including                   Terminology    of the Pyridine   Nucleotide   Coenzymes
Recommended       Symbols for Enzyme Kinetics, List of Cyto-                   Chapter 4 of the report makes important          recommendations
 chromes, a Key to Numbering         and Classification of Enzymes,         concerning the terminology       of these coenzymes: specifically,
and a List of Enzymes, classified and described by the system               that the coenzyme commonly known as DPN be called “nico-
 outlined in the Key. This list occupies approximately         half the     tinamide adeninc dinucleotide,”     and abbreviated as NAD; and
book.                                                                       t.hat the coeneymr previously denoted as TPK br named “nico-
    We believe that all biochemists should be aware of, and should          tinamide admine dinucleotide      phosphate,”    and abbreviated       as
 examine, this report.     Obviously not even a summary of its              N;\DP.       These abbreviations are now accepted by the Journal;
 contents can be given here. However, we note certain points.               authors are permitted to use either the old or the new abbrevia-
                                                                            tions for the coenzymcs, provided that a consistent usage is
            systematic Names and Code Numbers of Enqmes                     maintained in any single paper.
                                                                               In writing the equations for the interconversion     of the oxidized
   The report sets forth in detail a comprehensive attempt to               and reduced forms of the coenzymes, the Enzyme Commission
classify enzymes in terms of the types of reactions they catalyze,          Report offers alternative notations.      The Journal of Biological
and to give them systematic numbers and names in accordance                 Chemistry definitely favors the second of these notations, ac-
with the scheme outlined in the report.       Thus, for example, the
                                                                            cording to which one should writ.e
enzyme catalyzing the reaction: L-aspartate + 2-osoglutarate          =
oxaloacetatc + L-glutamate is assigned the code number 2.6.1 .I,                               NAD+   +NADH   + H+, or
and the systematic name L-aspartatc:          2-osoglutaratc     amino-                        ?;ADP+-+NADPH+   H+
transferasc.l   The report lists the corresponding       trivial name,         When speaking of thcso (soenzymes in general terms it is per-
“aspartatc aminotransferasc,”    or “aspartate transaminascx.”              missible to write ?;hD and NADP without the plus sign. How-
   The report offers the following proposal (page 49, Item 39),             ever, if the relation brtween the oxidized and reduced forms is
“Where an enzyme is the main subject of a paper or abstract,                under discussion, the plus sign should be used to balance the
it is recommcndrd that its code number, systematic name (where              charges.
a satisfactory one exists) and source should br given at its first             This terminology   has great advantages when coenzyme ana-
mention in the test; thercaftcr the trivial name may b(l used.”             logues are being discussed. For instance, 3-acetylpyridinc    adr-
   ‘The report follows the official terminology of the Chemical             nine dinucleotide may be shortenrd to 3-acetylpyridine-AD;     in a
Society (Great Britain) in using the term “oxoglutarate”  rather            figure or table where space is limited, or if it is mentioned very
than “ketoglutara.t,e.”                                                     frequently    in a paper, it may be shortened still further to

980                                                          Editorial   Comment                                          Vol. 237, n-o. 4

AcPy AD (the abbreviation P should not be used for pyridine since        longer system of abbreviations,     making use of the standard
it is the standard abbreviation         for a phosphate ester group).    abbreviation   NMN for nicotinamide      mononucleotide.    In this
Likewise, the structure of the compound previously denoted by            notation nicotinamide inosine dinucleotide could be abbreviated
many authors as desamino-DPN           is much more clearly designated   to NMN-IMP.        The extension of this system of notation to
as nicotinamide     inosine dinucleotide;    this could be abbreviated   other compounds is obvious.       Such abbreviations     should, of
as NID.      Alternatively,   it may be desirable to use a slightly      course, be defined in a footnote.

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