Solution structure of a biologically active cyclic LDV peptide analogue containing a type II′β-turn mimetic

The solution structure of cyclo‐[Gly‐Leu‐Asp‐Val‐BTD] (BTD=β‐turn dipeptide) has been determined by two‐dimensional 1H‐NMR (nuclear magnetic resonance) spectroscopy and systematic conformational searching combined with molecular dynamics studies. The structure contains two hydrogen bonds between the Gly and Val residues, and a type I β‐turn with Leu and Asp at the (i+ 1) and (i+ 2) positions of the turn. The cyclic compound shows activity in a scintillation proximity assay (SPA) for the inhibition of the interaction between the integrin α4β1 and vascular cell adhesion molecule‐1 (VCAM‐1). The structure‐activity relationship of the LDV sequence is discussed. © Munksgaard 1996.