P-sheet tapes

Robert P.W. Davies, Amalia Aggeli, Neville Boden, Tom C.B. McLeish, Irena A. Nyrkova, and Alexander N. Semenov, Mechanisms and Principles of ID Self-Assembly of Peptides into P -Sheet Tapes... 

Figure 4.9 Model for the hierarchical selforganization of A-l. (a) E forms tapes comprising two covalently linked single parallel P-sheet domains with opposite orientation, (b) F-l aggregate into more flexible and less stable single antiparallel P-sheet tapes, (c) Tapes obtained by parallel P-sheet formation from A-D are polar...

Figure 16 In situ AFM images of single P-sheet tapes grown on mica from 5 (XM Pu-2 in 10% H20 in 2-propanol. The tapes are aligned with the hexagonal symmetry of the underlying mica lattice (Whitehouse et al., 2005).

As an illustration of the second approach to biosynthesis, the work of Boden et al. will be taken as an example. Again the first step is to identify an interesting motif to be incorporated in a molecule. The motif that they have focussed on is the P-sheet. By incorporating a sequence which facilitates the formation of this structure it becomes possible to form a peptide which spontaneously self-assembles into P-sheet tapes. In appropriate solvents these peptides can form gels whose rheological properties can then be controlled by external parameters such as pH. Thus, what they have termed rational design coupled with the peptide synthesiser may yield macromolecules with a specific set of controlled properties. 

Aggeli A, Nyrkova lA, Bell M, Harding R, Carrick L, McLeish TCB, Semenov AN, Boden N (2001) Hierarchical self-assembly of chiral rod-like molecules as a model for peptide p-sheet tapes, ribbons, fibrils, and fibers. Proc Natl Acad Sci USA 98 11857-11862... 

Proto-tape (P-sheet tape) Hierarchy level II... 

Aggeli A, Bell M, Boden N, Keen JN, Knowles PF, McLeish TC, Pitkeathly M, Radford SE. Responsive gels formed by the spontaneous self-assembly of peptide into polymeric P-sheet tapes. Nature 1997 386 259-262. 

Aggeli, A., Bell, M., Boden, N., Keen, J. N., Knowles, P. F., McLeish, T. C., Pitkeathly, M., and Radford, S. E. (1997). Responsive gels formed by the spontaneous self-assembly of peptides into polymeric beta-sheet tapes. Nature 386, 259-262. 

Ribbon (P-sheet double tape) Hierarchy level III... 

Figure 32 Hierarchically structured composite fibers formed by a hybrid process, combining self-assembly of polymer-peptide nanotapes with peptide-directed silicification. ( Organic hierarchy levels are classified as peptide-polymer conjugate (level I), nanotapes with single p-sheet core (level II) and double p-sheet core (level III). Composite hierarchy levels are specified as proto-composite tapes (level IV), proto-composite fibers (level V), and fiber bundles (level VI).) Adapted from Kessel, S. Thomas, A. Borner, H. G. Angew. Chem., Int. Ed. 2007, 46, 9023 and Kessel, S. Bomer, H. G. Macromol. Rapid Commun. 2008,29,419. Reprinted with permission from Bomer, H. G. Prog. Polym. Sci. 2009,34,811. Copyright 2009, Elsevier. ...

Rudy J. Koopmans and Anton PJ. Middelberg, Engineering Materials from the Bottom Up — Overview Robert P W. Davies, Amalia Aggeli, Neville Boden, Tom C.B. McLeish, Irena A. Nyrkova, and Alexander N. Semenov, Mechanisms and Principles of 1 D Self-Assembly of Peptides into -Sheet Tapes Paul van der Schoot, Nucleation and Co-Operativity in Supramolecular Polymers MichaelJ. McPherson, Kier James, Stuart Kyle, Stephen Parsons, and Jessica Riley, Recombinant Production of Self-Assembling Peptides... 

Figure 4 (A) Schematic drawing of a p-barrei. (B) Modei of hierarchicai seif-assembiy of p-sheets. (c ) Locai arrangements and (c -f) the corresponding giobai equiiibrium conformations for the hierarchicai seif-assembiing structures formed in soiutions of (a) p-sheets, which aiign to form (c) tapes, then (d) twisted ribbons, then (e) fibriis, and (f) fibers, (e and f) The front views of the edges of fibriis and fibers, respectiveiy. Reproduced from Aggeii, A. Nytkova, i. A. Beii, M. etal. Proc. Natl. Acad. Sci. U.S.A. 2001, 98,11857-11862. Copyright 2001 Nationai Academy of Sciences, USA.

---