A recipe for designing water‐soluble, β‐sheet‐forming peptides

Abstract

Based on observations of solubility and folding properties of peptide 33-mers derived from the &sheet domains of platelet factor-4 (PF4), interleukin-8 (IL-8), and growth related protein (Gro-a), as well as other 6-sheet-forming peptides, general guidelines have been developed to aid in the design of water soluble, self-association-induced 0-sheet-forming peptides. CD, 'H-NMR, and pulsed field gradient NMR self-diffusion measurements have been used to assess the degree of folding and state of aggregation. PF4 peptide forms native-like @-sheet tetramers and is sparingly soluble above pH 6. IL-8 peptide is insoluble between pH 4.5 and pH 7.5, yet forms stable, nativelike &sheet dimers at higher pH. Gro-a peptide is soluble at all pH values, yet displays no discernable @-sheet structure even when diffusion data indicate dimer-tetramer aggregation. A recipe used in the de novo design of water-soluble 0-sheet-forming peptides calls for the peptide to contain 40-50~0 hydrophobic residues, usually aliphatic ones (I, L, V, A, M) (appropriately paired and mostly but not always alternating with polar residues in the sheet sequence), a positively charged (K, R) to negatively charged (E, D) residue ratio between 4/2 and 6/2, and a noncharged polar residue (N, Q, T, S) composition of about 20% or less. Results on four de novo designed, 33-residue peptides are presented supporting this approach; Under near physiologic conditions, all four peptides are soluble, form &sheet structures to varying degrees, and self-associate. One peptide folds as a stable, compact 0-sheet tetramer, whereas the others are transient 6-sheet-containing aggregates.

A folding pathway for βpep‐4 peptide 33mer: From unfolded monomers and β‐sheet sandwich dimers to well‐structured tetramers

“…A shoulder on the near-UV side of the main band appears to account for the 20% or so dimer (p-sheet) present. Present CD data also explain why earlier CD results on ppep-4 (Mayo et al, 1996) showed nearly equally intense CD bands at 204 nm and 217 nm. In that study, CD data were acquired using a peptide concentration of 0.1 1 mM [not the 10-20 mM as stated in the Figure 8 legend (erratum)].…”

“…aH resonances result from formation of well-folded P-sheet sandwich tetramers (Mayo et al, 1996;Ilyina et al, 1997aIlyina et al, , 1997b. As the ppep-4 peptide concentration is lowered at either temperature ( Fig.…”

Engineering of betabellin‐15d: A 64 residue beta sheet protein that forms long narrow multimeric fibrils

“…Fewer proteins have been designed with the P-sheet as the main element of secondary structure (Kullmann, 1984;Moser et al, 1985;Osterman & Kaiser, 1985; Richardson et al, 1992;Pessi et al, 1993; Quinn et al, 1994;Wagner et al, 1994;Krause et al, 1996;Mayo et al, 1996;Nesloney & Kelly, 1996;Smith & Regan, 1997; Zappacosta et al, 1997). Because P-sheets are less modular than a-helices and tend to aggregate in solution, it is more Reprint requests to: Bruce W. Erickson, Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; e-mail: bruce@peptide.chem.unc.edu.…”

Recognition of synthetic glycopeptides by HIV-1 broadly neutralizing antibodies and their unmutated ancestors

“…Our data demonstrate a clear role for the thiol of the Cys side chain in promoting/stabilizing the conformation of the glycopeptides via disulfide-linked dimer formation. Indeed, a known strategy for stabilization of designed β-sheetforming peptides in aqueous solutions involves dimerization (face-to-face or edge-to-edge) and intermolecular disulfide linkage (29)(30)(31)(32)(33), so the observed secondary-structure preferences could very well be due to a similar phenomenon. In our case, the best results were obtained when the oxidative dimerization was performed in aqueous DMSO.…”