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Minimal Information about MHC Multimers (MIAMM)


These guidelines were established with the expertise of the members of the NIH Tetramer Facility, laboratory users of such reagents, and database curators tasked with describing such reagents in machine-readable and interoperable digital resources. These minimal nomenclature guidelines for MHC Multimers will ensure that multimer data is presented according to the FAIR principles and is more Findable, Accessible, Interoperable and Reusable. Please see this publication explaining the standard -

See our Multimer Validator webtool to validate your multimers

Minimal Information about MHC Multimer (MIAMM) components and how they are standardized.

Component Standardization method Example Standardized name
MHC molecule MHC Restriction Ontology (MRO) A0201 HLA-A*02:01
Peptidic ligand Nomenclature Committee of the International Union of Biochemistry (IUPAC-IUB) SLYNTVATL SLYNTVATL
Non-peptidic ligand Chemical Entities of Biological Interest (ChEBI) α-GalCer 1-O-(α-D-galactosyl)-N-hexacosanoylphytosphingosine
Post translational modification Protein Modification Ontology (PSI-MOD) Acetylation acetylated residue
Modification position Letter followed by position in ligand the first leucine in SLYNTVATL L2

MHC molecules are described using the MHC Restriction ontology (MRO)[1].

Peptidic ligands are described using standard single letter abbreviations.

Non-peptidic ligands are described using Chemical Entities of Biological Interest (ChEBI)[2].

Post translational modifications of peptide ligands are described using Protein Modification Ontology (PSI-MOD)[3]. A table provided below provides the most commonly used modifications in multimer ligands.

Modification position within a peptide ligand is to be described by the single letter abbreviation of the amino acid that is modified, followed by the position of that amino acid within the peptide (L2).

For assistance following this standard, see the Multimer Validator, a web tool which allows users to either a) parse the full name they generated, and validate that it fulfills the specifications, or b) compose the full name, based on the information added by the user. The tool ensures that the valid ontology terms and nomenclatures are enforced. It can be used by entering multimers into a web form or by uploading a spreadsheet.

Common Modifications. Modifications commonly found in multimer ligands standardized using PSI-MOD terminology.

PSI-MOD label Synonym PSI-MOD ID
amidated residue Amidation, AMID MOD:00674
2-pyrrolidone-5-carboxylic acid (Glu) Pyrrolidone carboxylic acid, PYRE, PCA, pyroglutamic acid MOD:00420
9-fluorenylmethyloxycarbonyl (Fmoc) Fluorenylmethyloxycarbonyl, FMOC MOD:01109
acetylated residue Acetylation, ACET, AcRes, Acetyl MOD:02078
biotinylated residue Biotin, BIOT, BtnRes, Biotinylation MOD:01885
cysteinylation (disulfide with free L-cysteine) Cysteinylation, CYSTL, SCysCys MOD:00765
deamidated and methyl esterified residue Deamidation followed by a methylation, DEAME MOD:01369
deamidated residue Deamidation, DEAM, dNRes, Deamidated MOD:00400
dehydrated residue Dehydration, DEHY, Dehydrated MOD:00704
formylated residue Formylation, FORM, FoRes, Formyl MOD:00493
galactosylated residue Galactosylation, GAL, GalRes MOD:00728
glucosylated residue Glucosylation, GLUC, GlcRes, Glycation MOD:00726
glycosylated residue Glycosylation, GLYC, GlycoRes MOD:00693
hydroxylated residue Hydroxylation, HYL, HyRes MOD:00677
L-2-aminobutanoic acid (Glu) L-α-Aminobutyric acid, Abu MOD:00819
L-citrulline Citrullination, CITR, Cit, Deamidated MOD:00219
methylated residue Methylation, METH, METH, MeRes MOD:00427
myristoylated residue Myristoylation, MYRI, MYRI, MyrRes MOD:00438
mono N-acetylated residue N-acetylation, NAc, NAcRes, N-Acetyl MOD:00408
oxidized residue Oxidation, OX, OxRes MOD:00675
palmitoylated residue Palmitoylation PALM, PALM, PamRes, Palmitoyl MOD:00440
phosphorylated residue Phosphorylation, PHOS, PhosRes, Phospho MOD:00696
reduced residue Reduction, RED, RedRes MOD:01472
sulfated residue Sulfation, SULF, SulfRes, Sulfo MOD:00695
other OTH  

Edge Cases

Tethered peptides

Chimeric MHC molecules


  1. Vita R, Overton JA, Seymour E, Sidney J, Kaufman J, Tallmadge RL, Ellis S, Hammond J, Butcher GW, Sette A, Peters B. An ontology for major histocompatibility restriction. for major histocompatibility restriction. J Biomed Semantics. 2016 Jan 11;7:1. doi: 10.1186/s13326-016-0045-5. eCollection 2016.

  2. Hastings J, Owen G, Dekker A, Ennis M, Kale N, Muthukrishnan V, Turner S, Swainston N, Mendes P, Steinbeck C. (2016). ChEBI in 2016: Improved services and an expanding collection of metabolites. Nucleic Acids Res. 2016 Jan 4;44(D1):D1214-9.

  3. Montecchi-Palazzi L, Beavis R, Binz PA, Chalkley RJ, Cottrell J, Creasy D, Shofstahl J, Seymour SL, Garavelli JS. The PSI-MOD community standard for representation of protein modification data. Nat Biotechnol. 2008 Aug;26(8):864-6. doi: 10.1038/nbt0808-864.

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