Preferred Label : pros;
Detailed label : pros in histidine nomenclature;
IUPAC definition : The nitrogen atoms of the imidazole ring of histidine are denoted by i pros /i ('near',
abbreviated π) and i tele /i ('far', abbreviated τ) to show their position relative
to the side chain. This recommendation arose from the fact that two different systems
of numbering the atoms in the imidazole ring of histidine had both been used for a
considerable time (biochemists generally numbering as 1 the nitrogen atom adjacent
to the side chain, and organic chemists designating it as 3). The carbon atom between
the two ring nitrogen atoms is numbered 2 (as in imidazole), and the carbon atom next
to the τ nitrogen is numbered 5. The carbon atoms of the aliphatic chain are designated
α and β. This numbering should also be used for the decarboxylation product histamine
and for substituted histidine.;
Origin ID : P04890;
Automatic exact mappings (from CISMeF team)
- See also
The nitrogen atoms of the imidazole ring of histidine are denoted by i pros /i ('near',
abbreviated π) and i tele /i ('far', abbreviated τ) to show their position relative
to the side chain. This recommendation arose from the fact that two different systems
of numbering the atoms in the imidazole ring of histidine had both been used for a
considerable time (biochemists generally numbering as 1 the nitrogen atom adjacent
to the side chain, and organic chemists designating it as 3). The carbon atom between
the two ring nitrogen atoms is numbered 2 (as in imidazole), and the carbon atom next
to the τ nitrogen is numbered 5. The carbon atoms of the aliphatic chain are designated
α and β. This numbering should also be used for the decarboxylation product histamine
and for substituted histidine.
