Abstract
The betabellin target structure consists of 2 32-residue beta sheets packed against each other by hydrophobic interactions. We have designed, chemically synthesized, and biophysically characterized betabellin 14S, a single chain, and betabellin 14D, the disulfide-bridged double chain. The 32-residue nongenetic betabellin-14 chain (HSLTASIkaLTIHVQakTATCQVkaYTVHISE, a = D-Ala, k = D-Lys) has a palindromic pattern of polar (p), nonpolar (n), end (e), and beta-turn (t,r) residues (epnpnpnttnpnpnprrpnpnpnttnpnpnpe). Each half contains the same 14-residue palindromic pattern (underlined). Pairs of D-amino acid residues are used to favor formation of inverse-common (type-I') beta turns. In water at pH 6.5, the single chain of betabellin 14S is not folded, but the disulfide-linked betabellin 14D is folded into a stable beta-sheet structure. Thus, folding of the covalent dimer beta-bellin 14D is induced by formation of the single interchain disulfide bond. The binary pattern of alternating polar and nonpolar residues of its beta-sheets is not sufficient to induce folding. Betabellin 14D is a very water-soluble (10 mg/mL), small (64 residues), nongenetic (12 D residues) beta-sheet protein with properties (well-dispersed proton NMR resonances; Tm = 58 degrees C and delta Hm = 106 kcal/mol at pH 5.5) like those of a native protein structure.
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Selected References
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- Engel M., Williams R. W., Erickson B. W. Designed coiled-coil proteins: synthesis and spectroscopy of two 78-residue alpha-helical dimers. Biochemistry. 1991 Apr 2;30(13):3161–3169. doi: 10.1021/bi00227a002. [DOI] [PubMed] [Google Scholar]
- Hahn K. W., Klis W. A., Stewart J. M. Design and synthesis of a peptide having chymotrypsin-like esterase activity. Science. 1990 Jun 22;248(4962):1544–1547. doi: 10.1126/science.2360048. [DOI] [PubMed] [Google Scholar]
- Handel T. M., Williams S. A., DeGrado W. F. Metal ion-dependent modulation of the dynamics of a designed protein. Science. 1993 Aug 13;261(5123):879–885. doi: 10.1126/science.8346440. [DOI] [PubMed] [Google Scholar]
- Hodges R. S., Semchuk P. D., Taneja A. K., Kay C. M., Parker J. M., Mant C. T. Protein design using model synthetic peptides. Pept Res. 1988 Sep-Oct;1(1):19–30. [PubMed] [Google Scholar]
- Kamtekar S., Schiffer J. M., Xiong H., Babik J. M., Hecht M. H. Protein design by binary patterning of polar and nonpolar amino acids. Science. 1993 Dec 10;262(5140):1680–1685. doi: 10.1126/science.8259512. [DOI] [PubMed] [Google Scholar]
- Pessi A., Bianchi E., Crameri A., Venturini S., Tramontano A., Sollazzo M. A designed metal-binding protein with a novel fold. Nature. 1993 Mar 25;362(6418):367–369. doi: 10.1038/362367a0. [DOI] [PubMed] [Google Scholar]
- Richardson J. S., Richardson D. C., Tweedy N. B., Gernert K. M., Quinn T. P., Hecht M. H., Erickson B. W., Yan Y., McClain R. D., Donlan M. E. Looking at proteins: representations, folding, packing, and design. Biophysical Society National Lecture, 1992. Biophys J. 1992 Nov;63(5):1185–1209. [PMC free article] [PubMed] [Google Scholar]
- Thomas D. C. Re: "Conditions for confounding of the risk ratio and of the odds ratio". Am J Epidemiol. 1986 Jan;123(1):200–201. doi: 10.1093/oxfordjournals.aje.a114219. [DOI] [PubMed] [Google Scholar]
- Wishart D. S., Sykes B. D., Richards F. M. The chemical shift index: a fast and simple method for the assignment of protein secondary structure through NMR spectroscopy. Biochemistry. 1992 Feb 18;31(6):1647–1651. doi: 10.1021/bi00121a010. [DOI] [PubMed] [Google Scholar]
- Yan Y., Tropsha A., Hermans J., Erickson B. W. Free energies for refolding of the common beta turn into the inverse-common beta turn: simulation of the role of D/L chirality. Proc Natl Acad Sci U S A. 1993 Aug 15;90(16):7898–7902. doi: 10.1073/pnas.90.16.7898. [DOI] [PMC free article] [PubMed] [Google Scholar]