Format

Send to

Choose Destination
Acta Crystallogr B. 1999 Jun 1;55(Pt 3):424-431.

Molecular aggregation in crystalline 1:1 complexes of hydrophobic D- and L-amino acids. I. The L-isoleucine series.

Author information

1
Department of Chemistry, University of Oslo, PO Box 1033, Blindern, N-0315 Oslo, Norway. bjornda@kjemi.uio.no

Abstract

The amino acid L-isoleucine has been cocrystallized with seven selected D-amino acids including D-methionine [L-isoleucine-D-methionine (1/1), C(6)H(13)NO(2).C(5)H(11)NO(2)S, amino-acid side chain R = -CH(2)-CH(2)-S-CH(3)] and a homologous series from D-alanine [L-isoleucine-D-alanine (1/1), C(6)H(13)NO(2).C(3)H(7)NO(2), R = -CH(3)] through D-alpha-aminobutyric acid [L-isoleucine-D-alpha-aminobutyric acid (1/1), C(6)H(13)NO(2).C(4)H(9)NO(2), R = -CH(2)-CH(3)] and D-norvaline [L-isoleucine-D-norvaline (1/1), C(6)H(13)NO(2).C(5)H(11)NO(2), R = -CH(2)-CH(2)-CH(3)] to D-norleucine [L-isoleucine-D-norleucine (1/1), C(6)H(13)NO(2).C(6)H(13)NO(2), R = -CH(2)-CH(2)-CH(2)-CH(3)] with linear side chains, and D-valine [L-isoleucine-D-valine (1/1), C(6)H(13)NO(2).C(5)H(11)NO(2), R = -CH-(CH(3))(2)] and D-leucine [L-isoleucine-D-leucine (1/1), C(6)H(13)NO(2).C(6)H(13)NO(2), R = -CH(2)-CH-(CH(3))(2)] with branched side chains. All the crystal structures are divided into distinct hydrophilic and hydrophobic layers. In the five complexes with amino acids with linear side chains the polar parts of the D- and L-amino acids are related by pseudo-glide-plane symmetry, and four of them have remarkably similar molecular arrangements. The D-valine and D-leucine complexes, on the other hand, are structurally quite different with the polar parts of the D- and L-amino acids related by pseudo-inversion. Differences in the hydrogen-bond pattern in the two molecular arrangements are discussed.

PMID:
10927385

Supplemental Content

Full text links

Icon for International Union of Crystallography Icon for Norwegian BIBSYS system
Loading ...
Support Center