• 1 January 1985
    • journal article
    • research article
    • Vol. 25  (6) , 615-621
Abstract
The possible conformations of SMS 201-995, an active analog of somastostatin, were studied in dimethylsulfoxide solution by 500 MHz proton NMR spectroscopy. The assignments were made by use of 2D-correlated methods to detect long-range coupling connectivities in aromatic residues and between the .alpha. protons of consecutive residues. NOESY [2-dimesional nuclear Overhauser effects spectroscopy] experiments correlated amide and .alpha. protons of neighboring amino acid residues, which indicate a less flexible situation than in water. Measurements of temperature coefficients of the amide protons, of NH-C.alpha.H coupling constants and NOE effects are in favor of one predominant conformation with a .beta. turn, of type II'', involving amino acids Phe3 to Thr6.