AMA Manual of Style - Stacy L. Christiansen, Cheryl Iverson 2020
Molecular Medicine
Nomenclature
Molecules and their interactions underlie every area of medicine. Many classes of molecules are described according to rules or conventions, some of which are covered in other sections of this chapter. The Joint Commission on Biochemical Nomenclature formulates nomenclature policy for classes of biochemicals.1 The Joint Commission on Biochemical Nomenclature enzyme nomenclature is described in 14.10.3, Enzyme Nomenclature.2 The US National Center for Biotechnology Information is a searchable information resource on molecular biology with links to databases.3
This section provides information on various molecular terms, including expansions, derivations, typography, and usage information (but not rules for naming molecules). It is meant to assist the editor or reader encountering an unfamiliar term and to guide the author in using such terms. For terms not described herein, helpful sources include the Medical Subject Headings database of the National Library of Medicine,4 medical texts and dictionaries, and internet searches. For a review of molecular biology databases, see the 2016 Database Issue of Nucleic Acids Research.5
14.10.1 Molecular Terminology: Other Sections of Chapter 14.
The following sections of chapter 14 have subsections on molecular terms: 14.2, Cancer; 14.3, Cardiology; and 14.11, Neurology. The following sections of chapter 14 substantially deal with molecular terminology: 14.1, Blood Groups, Platelet Antigens, and Granulocyte Antigens; 14.6, Genetics; 14.7, Hemostasis; and 14.8, Immunology.
Table 14.10-1 gives molecular terms associated with subjects covered elsewhere in this chapter.
Table 14.10-1. Molecular Terms and Chapter Section Numbers
Entity |
Section |
amino acids |
14.6.1, Nucleic Acids and Amino Acids |
antitrypsins, antithrombins |
14.7.4, Inhibition of Coagulation and Fibrinolysis |
apolipoproteins |
14.3.12, Cellular and Molecular Cardiology |
bacterial strains and proteins |
14.14.2, Bacteria: Additional Terminology |
blood gas terminology (eg, PaO2) |
14.16, Pulmonary and Respiratory Terminology |
cancer molecules |
14.2.5, Molecular Cancer Terminology 14.6.3, Oncogenes and Tumor Suppressor Genes |
cellular adhesion molecules |
14.7.2, Endothelial Factors 14.8, Immunology |
chemokines |
14.8, Immunology |
chromosomes |
14.6.4, Human Chromosomes |
cloning vectors |
14.6.1, Nucleic Acids and Amino Acids |
clotting factors |
14.7.3, Secondary Hemostasis (Amplification and Propagation) |
clusters of differentiation (CDs) |
14.8, Immunology 14.1.2, Platelet-Specific Antigens |
codons |
14.6.1, Nucleic Acids and Amino Acids |
colony-stimulating factors |
14.8, Immunology |
complement |
14.8, Immunology |
creatine kinases |
14.3.12, Cellular and Molecular Cardiology |
cytokines |
14.8, Immunology |
D-dimer |
14.7.4, Inhibition of Coagulation and Fibrinolysis |
DNA |
14.6.1, Nucleic Acids and Amino Acids |
genes |
14.6.2, Human Gene Nomenclature 14.6.3, Oncogenes and Tumor Suppressor Genes 14.6.5, Nonhuman Genetic Terms |
glycoproteins |
14.1.2, Platelet-Specific Antigens 14.7.1, Primary Hemostasis (Initiation) 14.7.2, Endothelial Factors |
guanine nucleotides |
14.3.12, Cellular and Molecular Cardiology 14.6.1, Nucleic Acids and Amino Acids |
hemostatic molecules |
14.7.1, Primary Hemostasis (Initiation) |
hepatitis antigens and antibodies |
14.14.3, Virus Nomenclature |
histones |
14.6.1, Nucleic Acids and Amino Acids |
HLA antigens |
14.8, Immunology |
immunoglobulins |
14.8, Immunology |
influenza types and strains |
14.14.3, Virus Nomenclature |
integrins |
14.7.2, Endothelial Factors |
interferon |
14.8, Immunology |
interleukins |
14.8, Immunology |
ion channels |
14.11.5, Molecular Neuroscience |
lipoproteins |
14.3.12, Cellular and Molecular Cardiology |
muscle cell components |
14.3.12, Cellular and Molecular Cardiology |
mutations |
14.6.1, Nucleic Acids and Amino Acids |
myosin chains |
14.7.1, Primary Hemostasis (Initiation) |
neurotransmitters and receptors |
14.11.5, Molecular Neuroscience |
nitric oxide synthase |
14.3.12, Cellular and Molecular Cardiology 14.7.2, Endothelial Factors |
nodal cells |
14.3.12, Cellular and Molecular Cardiology |
nucleic acid technology (eg, polymerase chain reaction [PCR], single-nucleotide variations [SNVs] (formerly single-nucleotide polymorphisms [SNPs]), short tandem repeats [STRs]) |
14.6.1, Nucleic Acids and Amino Acids |
nucleosides, nucleotides |
14.6.1, Nucleic Acids and Amino Acids |
phages |
14.14.3, Virus Nomenclature |
phospholipase |
14.7.1, Primary Hemostasis (Initiation) |
plasminogen activators |
14.3.12, Cellular and Molecular Cardiology 14.7.2, Endothelial Factors |
platelet-activating factors |
14.7.1, Primary Hemostasis (Initiation) |
prions |
14.14.3, Virus Nomenclature |
prostaglandins |
14.7.1, Primary Hemostasis (Initiation) |
restriction enzymes |
14.6.1, Nucleic Acids and Amino Acids |
retrovirus gene terms |
14.6.3, Oncogenes and Tumor Suppressor Genes 14.6.5, Nonhuman Genetic Terms |
RNA |
14.6.1, Nucleic Acids and Amino Acids |
serotonin |
14.11.5, Molecular Neuroscience |
thromboxanes |
14.7.1, Primary Hemostasis (Initiation) |
troponins |
14.3.12, Cellular and Molecular Cardiology |
von Willebrand factor |
14.7.3, Secondary Hemostasis (Amplification and Propagation) |
14.10.2 Molecular Terms: Considerations and Examples.
Molecular terms often are more familiar in unexpanded form; their expansions may be obscure. Molecular terms often mix numbers, letters, and cases. They may be abbreviations or abbreviations within abbreviations (for instance, see TAF and subsequent entries in Table 14.10-2). Molecular terms differ from standard abbreviations, which typically are uppercase initialisms (eg, PVC for premature ventricular contraction). In contrast, many molecular terms are (or incorporate) contractions of single words, using all lowercase letters or mixing capital and lowercase letters (eg, apo for apolipoprotein; Hb for hemoglobin).
Letter prefixes (including Greek letters) and numeric prefixes are linked to the main term by hyphens.
α1-antitrypsin
β-catenin
λ-tubulin
glucose 6-phosphate
However, these terms are not hyphenated:
α helix
β sheet
Hyphens are added in adjectival usages:
β-pleated sheet
glucose-6-phosphate dehydrogenase
Hyphens are used as follows in numbers that interrupt a word:
propan-1,2-diol (propanol)
flavan-3-ol
For letter or number suffixes, hyphens typically are not used with expanded terms but are handled in various ways with abbreviated terms:
interleukin 1 (IL-1)
phosphodiesterase 3A (PDE3A)
6-keto prostaglandin F1α (6-keto PGF1α)
The chemical prefixes L (levo) and D (dextro) are small capitals when referring to biomolecules, such as amino acids and carbohydrates, in the D/L system of configuration.
L-folinic acid
D-glutaraldehyde
Element symbols in chemical names, such as S (sulfur) and N (nitrogen), are italicized. Other capital letters are not italicized.
N-acetyl-D-glucosamine
cytochrome P450
N-terminal, C-terminal
D-dimer
A subscript letter indicates a modifier of the main term.
Pi (inorganic phosphate)
Plus signs and minus signs that indicate charges are set superscript. Numerals that indicate quantities of an element within a molecule are set subscript. Numerals that indicate a charge are set superscript.
HCO3−
Fe3+
Although proteins may often be expressed as p plus a numeral signifying the atomic weight in kilodaltons (eg, p53, a 53-kDa protein), p53 is an alias or nickname and should be replaced with the official symbol, TP53 (see Table 14.10-2 and 14.6.3.2, Tumor Suppressor Genes). Affixes, such as superscripts, further specify the protein (important because different proteins may have the same weight) (Table 14.10-2). Although the gene symbols for such proteins are often given as the same term italicized (eg, the tumor suppressor gene p53), the correct gene symbols should be used (eg, in humans TP53, in mice, Tp53). Use the search feature at the HUGO Gene Nomenclature Committee website6 (see 14.6, Genetics).
The term stem cell has the general meaning of a precursor, pluripotent, or progenitor cell. Research articles should specify the type(s) of stem cell referred to, for example, adult, bone marrow, embryonic, germline, hematopoietic, mesenchymal, neural, peripheral blood, somatic, umbilical cord—derived, unrestricted somatic, and so forth. (The preceding terms are not all mutually exclusive.)
Terms in Table 14.10-2 are included as a reference. Some context or explanation of such terms is desirable at first mention, but, in contrast to abbreviations (see 13.0, Abbreviations), first mention need not be a literal expansion and the term may be stated as an appositive rather than in parentheses:
the cyclin-dependent kinase CDK2
When an abbreviation is used in the Suggested Usage at First Mention column in Table 14.10-2, it is assumed that in the article the abbreviated term has already been introduced and defined or expanded; for example, if INK4 (an alias [not the official symbol] for CDKN2A) is defined as “inhibitors of CDK4” at first mention, it is assumed that CDK4 was previously defined or expanded. Providing more information is often helpful. For instance, at first mention, CDKN1A (alias [not the official symbol]: p21) may be referred to as “cyclin-dependent kinase (CDK) inhibitor 1A” or given additional context (see Table 14.10-2 for further explanation of these terms).
Table 14.10-2. Molecular Terms and Explanations
Official term (aliasa) |
Explanation |
Suggested usage at first mention |
Aβ peptide, Aβ42 |
amyloid-β peptide |
amyloid-β peptide (Aβ), Aβ42 peptide, or 42-residue form of Aβ |
Aβ*56 |
56-kDa Aβ fragment |
56-kDa Aβ fragment |
Ach |
acetylcholine |
acetylcholine |
Acrp30 (or adiponectin) |
adipocyte-complement—related 30-kDa protein |
the protein Acrp30 or adiponectin |
acyl-CoA |
acyl derivatives of coenzyme A |
acyl coenzyme A |
acyl-S-CoA |
sulfonated acyl-CoA |
sulfonated acyl—coenzyme A |
ADAMTS7 |
a disintegrin like and metalloprotease domain (reprolysin-type) with thrombospondin type 1 motifs |
ADAMTS protease |
specific ADAMTS, eg, ADAMTS-13 |
ADAMTS-13; trivial name von Willebrand factor (VWF) protease (see 14.7, Hemostasis) |
ADAMTS-13 and/or vWFc protease |
adoHcy |
S-adenosylhomocysteine |
S-adenosylhomocysteine |
ado-Met (also SAM) |
S-adenosylmethionine |
S-adenosylmethionine |
Akt kinase |
a serine-threonine kinase, also known as protein kinase B, related to akt oncogene (origin: AKT retrovirus isolated from AKR mouse thymoma) |
Akt protein kinase |
allo-SCT |
allogeneic stem cell transplant |
allogeneic stem cell transplant |
ATCase |
aspartate transcarbamoylase |
aspartate transcarbamoylase |
ATPase |
adenosine triphosphatase |
adenosine triphosphatase |
BNP |
brain (or b-type) natriuretic peptide |
brain (or b-type) natriuretic peptide |
1,3-BPG |
1,3-bisphosphoglycerate |
1,3-bisphosphoglycerate |
CAK (or cyclin H/CDK7) |
CDK-activating enzyme |
the CDK-activating enzyme (CAK) cyclin H/CDK7 |
CaM |
calmodulin |
calmodulin |
CDK2, CDK3, CDK7, etc |
cyclin-dependent kinases |
the cyclin-dependent kinase CDK2, etc |
CDKI |
CDK inhibitors (see INK4 below) |
CDK inhibitors |
CoA |
coenzyme A |
coenzyme A |
COX-1, COX-2 |
cyclooxygenases 1 and 2 |
cyclooxygenase 1 (COX-1), cyclooxygenase 2 (COX-2) |
C-reactive protein |
protein reactive to pneumococcal cell wall C polysaccharide |
C-reactive protein (CRP) |
cyclin D/CDK4/CDK6, cyclin E/CDK2 |
cyclin-CDK complexes |
the cyclin D/CDK4/CDK6 complex; the cyclin E/CDK2 complex |
CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4 |
isoforms of cytochrome P450 enzymes (also cytochrome P450 isozymes) (P: pigment; 450: 450-nm absorbance) |
various, eg, cytochrome P450 1A2 isozyme (CYP1A2); cytochrome P450 3A4 isozyme (CYP3A4 or P450 3A4 or 3A4) |
Dkk-1 |
dickkopf-1 |
the inhibitor protein Dkk-1 |
F0 (subscript is zero, not capital O) |
portion of mitochondrial ATP synthase (F: energy-coupling factor) |
context, eg, F0 portion of mitochondrial ATP synthase, proton channel portion of ATP synthase, etc |
F0F1 |
complex portion of mitochondrial ATP synthase |
context, eg, F0F1 mitochondrial ATP synthase, F0F1 complex, etc |
F1 |
portion of mitochondrial ATP synthase |
context, eg, F1 portion of mitochondrial ATP synthase, catalytic portion of ATP synthase |
F1P, F6P |
fructose 1-phosphate, fructose 6-phosphate |
fructose 1-phosphate, fructose 6-phosphate |
FAD |
flavin adenine dinucleotide |
flavin adenine dinucleotide |
FADH2 |
reduced (hydrogenated) FAD |
FADH2or reduced (or hydrogenated) FAD |
FBPase-1, FBPase-2 |
fructose 1,6-bisphosphatase, fructose 2,6-bisphosphatase |
fructose 1,6-bisphosphatase, fructose 2,6-bisphosphatase |
Fd |
ferredoxin |
ferredoxin |
Fhit |
fragile histidine triad protein |
fragile histidine triad protein |
FMN |
flavin mononucleotide |
flavin mononucleotide |
FMNH2 |
reduced (hydrogenated) FMN |
FMNH2or reduced (or hydrogenated) FMN |
Fp |
flavoprotein |
flavoprotein (Fp) |
G0 |
quiescent state of cell cycle |
G0 phase |
G1 |
growth or gap 1 phase of cell cycle |
G1 phase |
G2 |
growth or gap 2 phase of cell cycle |
G2 phase |
G protein |
guanine triphosphate (GTP)—binding protein |
G protein |
Gα, Gβ, Gγ |
G protein families |
Gα, Gβ, Gγ protein or family |
Gα12, Gα13 |
members of Gα |
Gα12, Gα13 protein |
Gβγ, βγ |
Gβ subunit or complex |
Gβγ, βγ subunit or complex |
G1P, G6P |
glucose 1-phosphate, glucose 6-phosphate |
glucose 1-phosphate, glucose 6-phosphate |
GalN |
D-galactosamine |
D-galactosamine |
GalNAc |
N-acetyl-D-galactosamine |
N-acetyl-d-galactosamine |
Gi |
inhibitory G protein |
inhibitory G protein |
Glc or D-Glc |
D-glucose |
glucose orD-glucose |
Gq, Gq/11 |
classes of G protein |
Gq, Gq/11 protein |
Gs |
stimulatory G protein |
stimulatory G protein |
GlcA |
D-gluconic acid |
gluconic acid orD-gluconic acid |
GlcNAc (also NAG) |
N-acetyl-D-glucosamine |
N-acetyl-D-glucosamine GlcNAc |
GlcUA |
D-glucuronic acid |
D-glucuronic acid |
Grb2 |
growth factor receptor—bound protein 2 |
the protein Grb2 |
H2F (also DHF) |
dihydrofolate or 7,8-dihydrofolate |
dihydrofolate (H2F or DHF) or 7,8-dihydrofolate (H2F or DHF) |
H4F (also THF) |
tetrahydrofolate or 5,6,7,8-tetrahydrofolate |
tetrahydrofolate or 5,6,7,8-tetrahydrofolate |
Hb |
hemoglobin |
hemoglobin |
HbA1a, HbA1b, HbA1c |
glycated (not glycosylated; Lyn Reynolds, editorial office director, Diabetes, email communication, May 21, 2013) hemoglobin fractions |
preferred: glycated hemoglobin A1c (HbA1c), etc (also: glycohemoglobin A1c) |
HbCO |
carbon monoxyhemoglobin, carboxyhemoglobin |
carbon monoxyhemoglobin |
HbO2 |
oxyhemoglobin |
oxyhemoglobin |
HER2/neu |
from human epidermal growth factor receptor 2; preferred term is now ERBB2; see 14.6.3, Oncogenes and Tumor Suppressor Genes |
ERBB2 (formerly HER2 or HER2/neu) |
HMG-CoA |
β-hydroxy-β-methylglutaryl-CoA |
β-hydroxy-β-methylglutaryl-CoA (but statins, not HMG-CoA inhibitors) |
IKKβ |
IκB kinase β (I: inhibitor) |
IκB kinase β |
CDKN2A (INK4) |
inhibitors of CDK4 (see CDKI above and p16Ink4, etc, below) |
inhibitors of CDK4 |
IGF-1, IGF-2 |
insulinlike growth factor, type 1 and type 2 |
insulinlike growth factor 1, insulinlike growth factor 2 |
IGF-1R, IGF-22 |
IGF-1 receptor, IGF-2 receptor |
IGF-1 receptor, IGF-2 receptor |
IP3 |
inositol 1,4,5-triphosphate |
inositol 1,4,5-triphosphate |
α-KG |
α-ketoglutarate |
α-ketoglutarate |
lac |
lactose |
lactose |
M |
mitosis (phase of cell cycle) |
M phase |
Man |
D-mannose |
D-mannose |
Mb |
myoglobin (do not confuse with Mb, megabase, or MB, megabyte) |
myoglobin |
MbO2 |
oxymyoglobin |
oxymyoglobin |
M-CDK |
M-cyclin—CDK complex |
M-phase CDK |
Mcm proteins |
minichromosome maintenance proteins |
Mcm proteins |
M-cyclin |
M-kinase—cyclin complex |
M-cyclin |
M-kinase |
mitosis-phase kinase |
M-kinase |
Mur |
muramic acid |
muramic acid |
Mur2Ac (also NAM) |
N-acetylmuramic acid |
N-acetylmuramic acid |
NAD |
nicotinamide adenine dinucleotide |
nicotinamide adenine dinucleotide (NAD) or the nicotinamide coenzyme NAD |
NAD+ |
oxidized NAD |
NAD+ |
NADH |
reduced (hydrogenated) NAD |
reduced (or hydrogenated) NAD or NADH |
NADH hydrogenase |
NADH hydrogenase |
NADH hydrogenase |
NADP |
NAD phosphate |
NAD phosphate or NADP |
NADPH |
reduced (hydrogenated) NADP |
reduced (or hydrogenated) NADP or NADPH |
NAG |
(see GlcNAc above) |
|
Neu5Ac |
N-acetylneuraminic acid (sialic acid) |
N-acetylneuraminic acid |
NFκB |
nuclear factor—κB |
nuclear factor—κB (NF-κB or NF-B) |
NMDA |
N-methyl-D-aspartate |
N-methyl-D-aspartate |
NMN |
nicotinamide mononucleotide |
nicotinamide mononucleotide |
NMN+ |
oxidized NMN |
NMN+ |
NMNH |
reduced (hydrogenated) NMN |
reduced or hydrogenated NMN |
NMP |
nucleoside monophosphate |
nucleoside monophosphate |
NOx |
nitrogen oxides, such as nitrate, nitrite, and nitrosothiols; nitric oxide (NO) metabolites |
nitrogen oxides |
NPY |
neuropeptide Y |
neuropeptide Y |
NT-proBNP |
N-terminal fragment of the prohormone brain natriuretic peptide (see 14.6.1.5, Amino Acids) |
N-terminal fragment of the prohormone brain natriuretic peptide |
p16Ink4, p15Ink4B, p18Ink4C, p19Ink4D |
INK4s |
the INK4 p16Ink4, etc |
CDKN1A (p21) |
21-kDa protein |
the protein CDKN1A |
p21WAFI/CIP1, p27KIP1, p57KIP2 |
other CDKI; WAFI: wild-type p53-activated protein 1; CIP1: CDK-interacting protein 1; KIP: kinase inhibitor protein |
the CDKI p21WAFI/CIP1, etc |
TP53 (p53) |
53-kDa protein |
the protein TP53 |
CDKN1C (p57) |
57-kDa protein |
the protein CDKN1C |
PE, PPE |
protein or gene family named for amino acid sequence motif (PE: Pro-Glu, PPE: Pro-Pro-Glu; see 14.6.1, Nucleic Acids and Amino Acids) |
PE and PPE protein families, PE/PPE gene families, etc |
P-gp |
P-glycoprotein |
P-glycoprotein |
Pi |
inorganic phosphate |
inorganic phosphate |
PI |
phosphatidyl inositol |
phosphatidyl inositol |
PIP2 |
phosphatidylinositol 4,5-bisphosphate |
phosphatidylinositol 4,5-bisphosphate |
Pol |
polymerase (eg, DNA, RNA) |
polymerase |
PPi |
inorganic pyrophosphate |
inorganic pyrophosphate |
pRb |
retinoblastoma protein |
retinoblastoma protein |
PYY3-36 |
NPY receptor agonist (P: peptide; Y: NPY; Y: Y2 receptor; 3-36: 34 amino acid residue numbers) |
peptide YY3-36, the gut hormone PYY3-36 |
RANKL |
receptor-activated nuclear factor—κB ligand |
receptor-activated nuclear factor—κB ligand |
RecA protein, RecA |
recombinase A |
recombinase A |
RNAi |
RNA interference |
RNA interference |
R point |
restriction point (of cell cycle) |
R point |
RNase |
ribonuclease |
ribonuclease |
rTpo |
recombinant thrombopoietin |
recombinant thrombopoietin |
S |
DNA synthesis phase of cell cycle |
S phase or DNA synthesis phase |
S-cyclin |
S-kinase—cyclin complex |
S-cyclin |
sFlt-1 |
soluble fms-like tyrosine kinase 1 (fms: McDonough feline sarcoma [oncogene]) |
soluble fms-like tyrosine kinase 1 |
S-kinase |
synthesis-phase kinase |
S-kinase |
αSp22 |
22-kDa glycosylated form of α-synuclein |
22-kDa glycosylated α-synuclein |
αSyn |
α-synuclein |
α-synuclein |
TAF |
TBP-associated factor |
TATA-binding protein (TBP)—associated factor |
TAFII |
a class of TAFs |
a class of factors associated with TBP |
TATA box |
a DNA sequence rich in adenine (A) and thymidine (T) |
TATA box |
TBP |
TATA-binding protein |
TATA-binding protein |
TFIID |
complex of TBP and several TAFIIs |
TBP-TAFII complex |
UCP-1, UCP-2, UCP-3 |
uncoupling proteins |
uncoupling protein 1, and so on |
UDP-Gal |
uridine diphosphate galactose |
UDP-galactose |
UDP-Glc |
UDP-glucose |
UDP-glucose |
uE3 |
unconjugated estriol |
unconjugated E3 |
Wnt |
named for Drosophila melanogaster wingless mutant integration site |
the developmental protein Wnt, the Wnt signaling pathway, etc |
a Although these gene symbol aliases or nicknames, a result of their discovery before the completion of the Genome Project, may still be used by some, use of the approved gene symbol, not the alias, is strongly preferred. This usage will minimize confusion and make it possible to provide links to genomic databases for online versions of the article and to facilitate data retrieval in a number of databases. If an author insists on using an alias, provide the alias parenthetically after the approved gene symbol at first mention in text and abstract. This will link the two and provide a learning experience for those not yet familiar with the approved gene symbol.
14.10.3 Enzyme Nomenclature.
Enzyme nomenclature was formalized in the 1950s.2 It is formulated by the International Union of Biochemistry (IUB) and the International Union of Pure and Applied Chemistry (IUPAC), more specifically, the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB) and the IUPAC-IUB Joint Commission on Biochemical Nomenclature, and “is probably the single largest task of the committee.”2
Supplements of new enzymes are published annually. A complete list is available online.8 This list is searchable and includes the recommended name and number of each enzyme. Officially assigned names and numbers for enzymes are available at the Enzyme Nomenclature database,2 along with rules for enzyme nomenclature.
There are 3 types of enzyme names: recommended name (common, working, or trivial name), systematic name, and Enzyme Commission (EC) number. The recommended name is the name by which the enzyme is commonly known. The systematic name incorporates the reaction the enzyme catalyzes. The EC number is a unique identifier assigned to each enzyme.
Because systematic names can be unwieldy and recommended names are well known, recommended names are used in general medical publications. For unambiguous identification, the EC number, the systematic name, or both may be included at first mention.
The parts of the EC number are as follows:
class
subclass
sub-subclass
serial number within sub-subclass
The enzyme classes are as follows:
EC1 |
oxidoreductases |
EC2 |
transferases |
EC3 |
hydrolases |
EC4 |
lyases |
EC5 |
isomerases |
EC6 |
ligases |
Examples are shown in Table 14.10-3.
Table 14.10-3. Examples of Enzyme Class (EC) Names
EC No. |
Recommended name |
Systematic name |
EC 1.11.1.7 |
peroxidase |
phenolic donor:hydrogen-peroxide oxidoreductase |
EC 2.3.3.10 (formerly EC 4.1.3.5) |
hydroxymethylglutaryl-CoA synthase |
acetyl-CoA:acetoacetyl-CoA C-acetyltransferase |
EC 2.7.1.1 |
hexokinase |
ATP:D-hexose 6-phosphotransferase |
EC 3.1.1.7 |
acetylcholinesterase |
acetylcholine acetylhydrolase |
EC 3.5.2.6 |
β-lactamase |
β-lactam hydrolase |
EC 5.4.2.2 |
phosphoglucomutase |
α-D-glucose 1,6-phosphomutase |
EC 6.5.1.1 |
DNA ligase (ATP) |
poly(deoxyribonucleotide):poly (deoxyribonucleotide) ligase (AMP-forming) |
Principal Author: Cheryl Iverson, MA
Acknowledgment
Thanks to Boris C. Pasche, MD, PhD, Wake Forest Baptist Medical Center, Winston-Salem, North Carolina, and Mary L. (Nora) Disis, MD, JAMA Oncology, and Tumor Vaccine Medical Oncology, University of Washington, Seattle.
References
1.Biochemical Nomenclature Committees: International Union of Pure and Applied Chemistry and International Union of Biochemistry and Molecular Biology: IUPAC-IUBMB Joint Commission on Biochemical Nomenclature (JCBN) website. Updated July 23, 2019. Accessed August 1, 2019. https://www.qmul.ac.uk/sbcs/iubmb/
2.Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB). Enzyme Nomenclature database. Updated July 23, 2019. Accessed August 1, 2019. https://www.qmul.ac.uk/sbcs/iubmb/enzyme/
3.National Center for Biotechnology Information website. Accessed August 1, 2019. https://www.ncbi.nlm.nih.gov
4.Medical Subject Headings (MeSH): National Library of Medicine. Accessed August 1, 2019. https://www.ncbi.nlm.nih.gov/mesh
5.Rigden DJ, Fernández-Suárez XM, Galperin MY. The 2016 database issue of Nucleic Acids Research and an updated molecular biology database collection. Nucleic Acids Res. 2016;44(D1):D1-D6. doi:10.1093/nar/gkv1356
6.HUGO Gene Nomenclature Committee (HGNC) website. Accessed August 1, 2019. https://www.genenames.org/
7.ADAMTS13 gene. Published April 20, 2015. Accessed May 8, 2018. https://ghr.nlm.nih.gov/gene/ADAMTS13
8.McDonald AG, Boyce S, Tipton KF. ExporEnz: the primary source of the IUBMB enzyme list. Nucl Acids Res. 2009:37:D593-D597. doi:10.1093/nar/gkn582. https://www.gmul.ac.uk./sbcs/iubmb/enzyme/