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De novo design of a monomeric three‐stranded antiparallel β‐sheet
Author(s) -
Alba Eva De,
Santoro Jorge,
Rico Manuel,
Jiménez M. Angeles
Publication year - 1999
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.8.4.854
Subject(s) - antiparallel (mathematics) , beta sheet , peptide , chemistry , sedimentation equilibrium , nuclear magnetic resonance spectroscopy , monomer , crystallography , peptide sequence , protein structure , chemical shift , random coil , stereochemistry , circular dichroism , biochemistry , ultracentrifuge , physics , organic chemistry , polymer , quantum mechanics , magnetic field , gene
Here we describe the NMR conformational study of a 20‐residue linear peptide designed to fold into a monomeric three‐stranded antiparallel β‐sheet in aqueous solution. Experimental and statistical data on amino acid β‐turn and β‐sheet propensities, cross‐strand side‐chain interactions, solubility criteria, and our previous experience with β‐hairpins were considered for a rational selection of the peptide sequence. Sedimentation equilibrium measurements and NMR dilution experiments provide evidence that the peptide is monomeric. Analysis of 1 H and 13 C‐NMR parameters of the peptide, in particular NOEs and chemical shifts, and comparison with data obtained for two 12‐residue peptides encompassing the N‐ and C‐segments of the designed sequence indicates that the 20‐residue peptide folds into the expected conformation. Assuming a two‐state model, the exchange kinetics between the β‐sheet and the unfolded peptide molecules is in a suitable range to estimate the folding rate on the basis of the NMR linewidths of several resonances. The time constant for the coil‐β‐sheet transition is of the order of several microseconds in the designed peptide. Future designs based on this peptide system are expected to contribute greatly to our knowledge of the many factors involved in β‐sheet formation and stability.