The Biological Significance of cis-trans Isomerism

Cxxxv. the Biological Significance of Cis-trans Isomerism

A graph theoretical approach to cis/trans isomerism

Abstract: A simple graph-theory-based model is presented, by means of which it is possible to express the energy difference between geometrically non-equivalent forms of a conjugated polyene. This is achieved by modifying the adjacency matrix of the molecular graph, and including into it information on cis/trans constellations. The total π-electron energy thus calculated is in excellent agreeme...

cis–trans-Amide isomerism of the 3,4-dehydroproline residue, the ‘unpuckered’ proline

Proline (Pro) is an outstanding amino acid in various biochemical and physicochemical perspectives, especially when considering the cis-trans isomerism of the peptidyl-Pro amide bond. Elucidation of the roles of Pro in chemical or biological systems and engineering of its features can be addressed with various Pro analogues. Here we report an experimental work investigating the basic physicoche...

Characteristic structural features of indolicidin: effects of the cis-trans isomerism on its conformation.

Indolicidin is an antimicrobial peptide showing a broad spectrum of antibacterial and antifungal activities, and according to the cis-trans isomerism of three Xaa-Pro peptide bonds, eight different stereoisomers could be distinguished for this peptide. As the cis-trans isomerism about the Xaa-Pro peptide bonds was not considered in previous studies, the structural features of distinct stereoiso...

Electronic tuning of Mo2(thioamidate)4 complexes through π-system substituents and cis/trans isomerism.

We report an exploration of the coordination chemistry of a systematic series of cyclic thioamidate ligands with the quadruply-bonded Mo2(4+) core. In addition to the S and N donor atoms that bind to Mo, the ligands utilized in this study have an additional O or S atom in conjugation with the thioamidate π system. The preparation of four new Mo2 complexes is described, and these compounds are c...