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Claudio Toniolo

Bio: Claudio Toniolo is an academic researcher from University of Padua. The author has contributed to research in topics: Circular dichroism & Peptide. The author has an hindex of 65, co-authored 761 publications receiving 19239 citations. Previous affiliations of Claudio Toniolo include Brown University & Max Planck Society.


Papers
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Journal ArticleDOI
TL;DR: The preferred conformations of peptides heavily based on the currently extensively exploited achiral and chiral α-amino acids with a quaternary α-carbon atom, as determined by conformational energy computations, crystal-state (x-ray diffraction) analyses, and solution (1H-NMR and spectroscopic) investigations, are reviewed in this paper.
Abstract: The preferred conformations of peptides heavily based on the currently extensively exploited achiral and chiral α-amino acids with a quaternary α-carbon atom, as determined by conformational energy computations, crystal-state (x-ray diffraction) analyses, and solution (1H-NMR and spectroscopic) investigations, are reviewed. It is concluded that 310/α-helical structures and the fully extended (C5) conformation are preferentially adopted by peptide sequences characterized by this family of amino acids, depending upon overall bulkiness and nature (e.g., whether acyclic or C ↔ C cyclized) of their side chains. The intriguing relationship between α-carbon chirality and bend/helix handedness is also illustrated. γ-Bends and semiextended conformations are rarely observed. Formation of β-sheet structures is prevented. © 2002 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 60: 396–419, 2001

588 citations

Journal ArticleDOI
TL;DR: The structural preferences of homopeptides from Aib(α-aminoisobutyric acid), Deg(Cα, α-diethylglycine), Dpg(C α, α -dipropyl glycine) and Ac n c(1-aminocycloalkane-1-carboxylic acid; n=3,5,6) residues, as determined by conformational energy computations, X-ray diffraction analyses, and spectroscopic studies, are reviewed as mentioned in this paper.
Abstract: The structural preferences of homopeptides from Aib(α-aminoisobutyric acid), Deg(Cα , α-diethylglycine), Dpg(Cα , α-dipropylglycine) and Ac n c(1-aminocycloalkane-1-carboxylic acid; n=3,5,6) residues, as determined by conformational energy computations, X-ray diffraction analyses, and spectroscopic studies, are reviewed. The results obtained indicate that the 3 10 -helix and the fully extended (C 5 ) conformation are preferentially adopted by long sequences of these Cα , α-disubstituted α-amino acid residues, depending upon bulkiness and nature (whether linear or cyclic) of their side chains

384 citations

Journal ArticleDOI
01 Jan 1980
TL;DR: This review focuses both on model peptides and biological activity polypeptide molecules and on intramolecularly hydrogen-bonded peptide structures involving a side-chain group, the N-protecting group, and a beta-amino acid.
Abstract: (1980). Intramolecularly Hydrogen-Bonded Peptide Conformation. Critical Reviews in Biochemistry: Vol. 9, No. 1, pp. 1-44.

343 citations

Journal ArticleDOI
TL;DR: The various types of conformationally restricted peptides obtained by short-range cyclizations, from residue i to residue i + 1, are presented and the pertinent literature listed.
Abstract: The various types of conformationally restricted peptides obtained by short-range cyclizations, from residue i to residue i + 1, are presented. Relevant examples of N in equilibrium C alpha, C' in equilibrium C alpha, N in equilibrium C', C alpha in equilibrium C alpha, C' in equilibrium C', and N in equilibrium N cyclizations are reported and the pertinent literature listed. In the discussion emphasis is place on the conformational consequences for peptides from the incorporation of such ring structures.

253 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: The present review aims to provide a reassessment of the factors important for folding in light of current knowledge, including contributions to the free energy of folding arising from electrostatics, hydrogen-bonding and van der Waals interactions, intrinsic propensities, and hydrophobic interactions.
Abstract: T e purpose of this review is to assess the nature and magnitudes of the dominant forces in protein folding. Since proteins are only marginally stable at room temperature,’ no type of molecular interaction is unimportant, and even small interactions can contribute significantly (positively or negatively) to stability (Alber, 1989a,b; Matthews, 1987a,b). However, the present review aims to identify only the largest forces that lead to the structural features of globular proteins: their extraordinary compactness, their core of nonpolar residues, and their considerable amounts of internal architecture. This review explores contributions to the free energy of folding arising from electrostatics (classical charge repulsions and ion pairing), hydrogen-bonding and van der Waals interactions, intrinsic propensities, and hydrophobic interactions. An earlier review by Kauzmann (1959) introduced the importance of hydrophobic interactions. His insights were particularly remarkable considering that he did not have the benefit of known protein structures, model studies, high-resolution calorimetry, mutational methods, or force-field or statistical mechanical results. The present review aims to provide a reassessment of the factors important for folding in light of current knowledge. Also considered here are the opposing forces, conformational entropy and electrostatics. The process of protein folding has been known for about 60 years. In 1902, Emil Fischer and Franz Hofmeister independently concluded that proteins were chains of covalently linked amino acids (Haschemeyer & Haschemeyer, 1973) but deeper understanding of protein structure and conformational change was hindered because of the difficulty in finding conditions for solubilization. Chick and Martin (191 1) were the first to discover the process of denaturation and to distinguish it from the process of aggregation. By 1925, the denaturation process was considered to be either hydrolysis of the peptide bond (Wu & Wu, 1925; Anson & Mirsky, 1925) or dehydration of the protein (Robertson, 1918). The view that protein denaturation was an unfolding process was

3,570 citations

PatentDOI
14 Nov 2002-Science
TL;DR: In this paper, pH-induced self-assembly of a peptide-amphiphile was used to make a nanostructured fibrous scaffold reminiscent of extracellular matrix.
Abstract: We have used the pH-induced self-assembly of a peptide-amphiphile to make a nanostructured fibrous scaffold reminiscent of extracellular matrix. The design of this peptide-amphiphile allows the nanofibers to be reversibly cross-linked to enhance or decrease their structural integrity. After cross-linking, the fibers are able to direct mineralization of hydroxyapatite to form a composite material in which the crystallographic c axes of hydroxyapatite are aligned with the long axes of the fibers. This alignment is the same as that observed between collagen fibrils and hydroxyapatite crystals in bone.

3,125 citations

Patent
29 Jun 2001
TL;DR: In this article, a structural signal called for the display of the protein on the outer surface of a chosen bacterial cell, bacterial spore or phage (genetic package) is introduced into a genetic package.
Abstract: In order to obtain a novel binding protein against a chosen target, DNA molecules, each encoding a protein comprising one of a family of similar potential binding domains and a structural signal calling for the display of the protein on the outer surface of a chosen bacterial cell, bacterial spore or phage (genetic package) are introduced into a genetic package. The protein is expressed and the potential binding domain is displayed on the outer surface of the package. The cells or viruses bearing the binding domains which recognize the target molecule are isolated and amplified. The successful binding domains are then characterized. One or more of these successful binding domains is used as a model for the design of a new family of potential binding domains, and the process is repeated until a novel binding domain having a desired affinity for the target molecule is obtained. In one embodiment, the first family of potential binding domains is related to bovine pancreatic trypsin inhibitor, the genetic package is M13 phage, and the protein includes the outer surface transport signal of the M13 gene III protein.

3,093 citations