[Relation between the structure of oligopeptides and the amino acid sequence]

The present paper deals with determination of the relationship between the order of the arrangement of amino acids in comparatively short-range oligopeptides (tetrapeptides) and their conformational potentialities. It is shown that the spatial and conformational possibilities of the tetrapeptides composed of the same amino acid residues exhibit high sensibility to their mutual arrangement, i. e. to the amino acid sequence. A detailed conformation analysis vividly demonstrated that the difference in conformational possibilities is manly determined by different conditions of realization of residual interactions. It is shown convincingly that energetic differences of the fragments are due to different interaction contributions for each of the considered fragments.