High-affinity peptide ligands

This approach is illustrated in Table 4 by compounds 54-60, in which residues 31-25 of NPY are sequentially added to the N-terminus of pentapeptide 16 (YRLRY-NH2). In this series, affinity for rat brain NPY receptors peaks at the decapeptide 58 

Compound Peptide-NH2 IC50 (nM) rat brain (Y2) EDso(nM) HEL cell (Y1) 

Rat brain binding data are presented as the IC50 calculated from non-linear regression analysis of the concentration-dependent displacement data (procedure as described in Table 1). Mobilization of calcium in HEL cells is expressed as the concentration of peptide that produces a half-maximal increase in the 340/380 nm fluorescence ratio in fura-2 loaded cells. For compound 62, we have observed, in a parallel series, that substitution of lle-5 by Leu had little effect on rat brain receptor binding. 

It has previously been demonstrated that appending an N-terminal segment of NPY (residues 1—4) linked by a flexible spacer on to NPY25 36 produces potent Y2- 

To complement H-NMR studies, an extended molecular dynamics simulation of 58 was carried out. The starting geometry for 58 was generated using coordinates taken from the partially helical, C-terminal decapeptide portion (residues 27-36) of the NPY model shown in Plate 13. The residues corresponding to Thr-32 and Gln-34 were replaced with Tyr and Leu, respectively, and subjected to an unconstrained molecular dynamics simulation. The structures obtained from this simulation (a representative structure is shown in Plate 15b) share several important features with those observed by H-NMR, specifically the formation of an Asx turn and close association of the aromatic tyrosine rings. 

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Pinilla C, Appel JR, Blanc P, Houghten RA, Rapid identification of high affinity peptide ligands using positional scanning synthetic peptide combinatorial libraries, BioTechniques, 13 901-902, 904—905, 1992. 

Linn H, Ermekova KS, Rentschler S, Sparks AB, Kay BK, Sudol M, Using molecular repertoires to identify high-affinity peptide ligands of the WW domain of human and mouse YAP, Biol. Chem., 378(6) 531-537, 1997. 

Pisabarro, M.T. Serrano, L. Wilmanns, M. Crystal structure of the abl-SH3 domain complexed with a designed high-affinity peptide ligand implications for SH3-ligand interactions. J. Mol. Biol., 281, 513-521 (1998)... 

Pisabarro, M. T, and Serrano, L. (1996). Rational design of specific high-affinity peptide ligands for the Abl-SH3 domain. Biochemistry 35, 10634-10640. 

Identification of High Affinity Peptide Ligands Using Positional Scanning Synthetic Peptide Combinatorial Libraries. 

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