Nomenclature and Symbolism for Amino Acids and Peptides

Examples for 3AA-17.2

This version of the examples for 3AA-17.2 does not use the HTML table format.

 Examples                                          Symbols  Notes (Note vi)
O4-Methyl hydrogen aspartate ([beta]-methyl aspartate) Note i

O5-Ethyl hydrogen N-acetylglutamate Note i

N6-Acetyllysine

O3-Acetylserine

O4-Sulfotyrosine (tyrosine O4-sulfate)

S-Ethylcysteine

3-Sulfenoalanine Note ii

S-Sulfocysteine (S-cysteinesulfonic acid) Note ii, iii

S-Cyanocysteine

Cystine

D-Cystine

meso-Cystine

Methionine S-oxide (methionine oxide) Note ii, iv

Methionine S,S-dioxide (methionine dioxide) Note ii, iv

Phosphoserine (O3-phosphonoserine) Note v

Nτ-Methylhistidine (telemethylhistidine, see 3AA-2.2.4)

Notes

(i) Asp-OMe represents the O1-methyl ester of aspartic acid (C-1 modification by 3AA-16.3), whereas Asp(OMe) represents the O 4-methyl ester (side-chain modification by 3AA-16.4.2).

(ii) Names based on cysteine and symbols based on Cys already indicate sulfur in the molecule, and similarly with methionine and Met. Indication of modification of this sulfur should not suggest the addition of further sulfur. Hence calling 3-sulfenoalanine by the name cysteinesulfenic acid, 3-sulfinoalanine by the name cysteinesulfinic acid. methionine S-oxide by the name methionine sulfoxide, and methionine S,S-dioxide by the name methionine sulfone may be confusing and is not recommended.

(iii) Care should be taken with this symbol because readers who fail to realize that the symbol Cys contains the sulfur may confuse it with cysteic acid, now symbolized Cya (3AA-15.2.6). The earlier [10] symbol for cysteic acid has the disadvantage that the vertical line in it does not represent a single bond.

(iv) The vertical lines or parentheses previously [10] in the symbols for MetO and MetO2 are now omitted, because they wrongly implied removal of hydrogen.

(v) -P represents -PO3H2 [24].

(vi) Entries are in the order Examples Symbols Notes but are not aligned into columns.


Return to 3AA-17.2.