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Removing the C‐terminal protecting group enlarges the crystal size: Z–(Gly–Aib) 2 –OH·H 2 O
Author(s) -
Gessmann Renate,
Brückner Hans,
Petratos Kyriacos
Publication year - 2020
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229620014254
Subject(s) - hydrogen bond , intermolecular force , intramolecular force , tetrapeptide , crystal structure , crystallography , chemistry , crystal (programming language) , aminoisobutyric acid , glycine , stereochemistry , molecule , amino acid , peptide , organic chemistry , biochemistry , computer science , programming language
The achiral tetrapeptide monohydrate N ‐(benzyloxycarbonyl)glycyl‐α‐aminoisobutyrylglycyl‐α‐aminoisobutyric acid monohydrate, Z–Gly–Aib–Gly–Aib–OH·H 2 O ( Z is benzyloxycarbonyl, Aib is α‐aminoisobutyric acid and Gly is glycine) or C 20 H 28 N 4 O 7 ·H 2 O, exhibits two conformations related by the symmetry operation of an inversion centre. It adopts only one of two possible intramolecular hydrogen bonds in a type I (and I′) β‐turn and forms a maximum of intermolecular hydrogen bonds partly mediated by water. The space group, the molecular structure and the crystal packing differ from two already described (Gly–Aib) 2 peptides which vary only in the protecting groups. This structure confirms the high structural flexibility of Gly–Aib peptides and points to a strong relationship between intermolecular hydrogen bonding and crystal quality and size.