Helix-coil energetics for helix formers and breakers reflect context and temperature: mutants of helically robust, guest-sensitive homopeptide hosts.

abstract：:For the controlled synthesis of even the simplest dipeptide, the N(alpha)-amino group of one of the amino acids and the C-terminal carboxyl group of the other should both be blocked with suitable protecting groups. Formation of the desired amide bond can now occur upon activation of the free carboxyl group. After coup...

journal_title：Biopolymers

authors： Albericio F

更新日期：2000-01-01 00:00:00

abstract：:The aim of this study was to investigate the effect of dopa and catecholamines on the generation of oxygen active species during oxidation of farmorubicin by "Fenton-like" reagents using chemiluminescent and spectrophotometric techniques. The tested catechols were found to reduce the light emission accompanying oxidat...

journal_title：Biopolymers

authors： Kruk I,Lichszteld K,Aboul-Enein HY

更新日期：2002-01-01 00:00:00

abstract：:Lung cancer is usually fatal once it becomes metastatic. However, in order to develop metastases, a tumor usually invades the basal membrane and enters the vascular or lymphatic system. In this study, a three-dimensional artificial membrane using collagen type I, one of the main components of basal membranes, was esta...

journal_title：Biopolymers

authors： Yang Y,Sulé-Suso J,Sockalingum GD,Kegelaer G,Manfait M,El Haj AJ

更新日期：2005-08-15 00:00:00

abstract：:The 83-residue conopeptide (p21a) and its corresponding nonhydroxylated analog were isolated from the injected venom of Conus purpurascens. The complete conopeptide sequences were derived from Edman degradation sequencing of fragments from tryptic, chymotryptic and cyanogen bromide digestions, p21a has a unique, 10-cy...

journal_title：Biopolymers

authors： Möller C,Marí F

更新日期：2011-01-01 00:00:00

abstract：:Circular dichroism using synchrotron radiation (SRCD) can extend the spectral range down to approximately 130 nm for dry proteins, potentially providing new structural information. Using a selection of dried model proteins, including alpha-helical, beta-sheet, and mixed-structure proteins, we observe a low-wavelength ...

journal_title：Biopolymers

authors： Nesgaard LW,Hoffmann SV,Andersen CB,Malmendal A,Otzen DE

更新日期：2008-09-01 00:00:00

abstract：:In this paper, we studied the quenching mechanism of intrinsic fluorescence of type I collagen by a new type photosensitizer and fluorescence quencher, hypocrellin B (HB). It was indicated that type I collagen can emit Tyr-intrinsic fluorescence with the excitation wavelength of Tyr (lambda(ex) = 269 nm). Its fluoresc...

journal_title：Biopolymers

authors： Li YH,Yue JC,Cai GP

更新日期：1997-08-01 00:00:00

abstract：:Study of model beta-hairpin peptides allows for better understanding of the factors involved in the formation of beta-sheet secondary structure in proteins. It is known that turn sequence, sidechain-sidechain interactions, interstrand hydrogen bonding, and beta-sheet propensity of residues are all important for beta-h...

journal_title：Biopolymers

authors： Riemen AJ,Waters ML

更新日期：2008-01-01 00:00:00

abstract：:Fluorescein-labeled antibodies are widely used in clinical assays and fluorescence microscopy. The fluorescent signal per labeled antibody is limited by fluorescein self-quenching, which occurs when the antibody is heavily labeled with multiple fluoresceins. We examined immunoglobulin G (IgG) when labeled with 0.7 to ...

journal_title：Biopolymers

authors： Lakowicz JR,Malicka J,Huang J,Gryczynski Z,Gryczynski I

更新日期：2004-08-15 00:00:00

abstract：:The presence of low pKa N-hydroxylamines is beneficial in peptide chemistry as they reduce some base-mediated side reactions. Here we evaluated the applicability and buffering capacity of Ethyl 2-cyano-2-(hydroxyimino) acetate (Oxyma) in the prevention of aspartimide/piperidide formation and Pro-based overcoupling and...

journal_title：Biopolymers

authors： Subirós-Funosas R,El-Faham A,Albericio F

更新日期：2012-01-01 00:00:00

abstract：:Using internal conformational degrees of freedom for biopolymers as natural variables, and introducing a Lagrangian dynamics approach, one can simulate time-dependent processes over a much longer time scale than in classical Newtonian molecular dynamics (MD) techniques. Two factors contribute to this: a substantial re...

journal_title：Biopolymers

authors： Rudnicki WR,Lesyng B,Harvey SC

更新日期：1994-03-01 00:00:00

abstract：:Polymeric macromolecules, when viewed abstractly as strings of symbols, can be treated in terms of formal language theory, providing a mathematical foundation for characterizing such strings both as collections and in terms of their individual structures. In addition this approach offers a framework for analysis of ma...

journal_title：Biopolymers

authors： Searls DB

更新日期：2013-03-01 00:00:00

abstract：:Near uv CD spectra of Trp residues in proteins frequently show a complex line shape deriving from the overlap of 1La and 1Lb electronic transitions. This study presents an original empirical method of resolving these components, based on the near uv CD spectra of well-defined complexes of calmodulin domains with targe...

journal_title：Biopolymers

authors： Barth A,Martin SR,Bayley PM

更新日期：1998-06-01 00:00:00

abstract：:Porins from outer membrane of Gram-negative bacteria have a highly stable structure. Our previous studies on porin from Paracoccus denitrificans showed that the outer membrane protein porin is extremely stable toward heat, pH, and chemical denaturants. The major question we have addressed in this paper is whether the ...

journal_title：Biopolymers

authors： Sukumaran S,Hauser K,Maier E,Benz R,Mäntele W

更新日期：2006-07-01 00:00:00

abstract：:The conformational preferences of blocked alanine dipeptide (ADP), Ac-Ala-NHMe, in aqueous solution were studied using vibrational circular dichroism (VCD) together with density functional theory (DFT) calculations. DFT calculations of three most representative conformations of ADP surrounded by six explicit water mol...

journal_title：Biopolymers

authors： Mirtič A,Merzel F,Grdadolnik J

更新日期：2014-07-01 00:00:00

abstract：:The solution structure of a hexapeptide, cyclo (Gln-Trp-Phe-Gly-Leu-Met), which is a selective NK-2 antagonist, has been studied by a combination of two-dimensional nmr and molecular dynamics (MD) techniques. The simulation based on nmr and MD data resulted in the convergence to a family of structures. Free molecular ...

journal_title：Biopolymers

authors： Zhang M,Quinn TP,Wong TC

更新日期：1994-09-01 00:00:00

abstract：:Pig citrate synthase (PCS) can be used as a model enzyme to gain some insight into the structural basis of protein thermostability. The thermal unfolding characteristics of the specific secondary structure elements within PCS were monitored in detail by following changes in its amide I band components. The result of o...

journal_title：Biopolymers

authors： Severcan F,Haris PI

更新日期：2003-08-01 00:00:00

abstract：:Synthetic model membrane-interactive peptides--both of natural and designed sequence--have become convenient and systematic tools for determination of how the membrane-spanning segments within integral membrane proteins confer protein structure and biology. Conformational studies on these peptides demonstrate that the...

journal_title：Biopolymers

authors： Deber CM,Li SC

更新日期：1995-01-01 00:00:00

abstract：:Molecular dynamics simulation, with backbone constraints for 20 ps of equilibration and simulation, of a repeating polypeptide segment, Gln-Pro-His-Gln-Pro-Leu-Gln-Pro-His-Gln-Pro-Leu-Gln-Pro-Met-(Gln-Pro-Leu )4, constituting residues 112-138 of bovine amelolgenin, a 19.35 kD hydrophobic protein, are discussed. It is ...

journal_title：Biopolymers

authors： Renugopalakrishnan V,Pattabiraman N,Prabhakaran M,Strawich E,Glimcher MJ

更新日期：1989-01-01 00:00:00

abstract：:Interactions between biological macromolecules have characteristic values of affinity and specificity that are set according to the biological function that is served by the interaction in the organism. Here we examine the molecular mechanisms that are used to achieve the required values of affinity and specificity in...

journal_title：Biopolymers

authors： Szwajkajzer D,Carey J

更新日期：1997-01-01 00:00:00

abstract：:Recent studies on the conformational preferences of the Dphig (C(alpha,alpha)-diphenylglycine) residue showed that this C(alpha,alpha)-disubstituted glycine has a structural versatility. In fact, depending on the nature of the following or preceding residue, Dphig can assume either folded or extended conformations. We...

journal_title：Biopolymers

authors： Pavone V,Lombardi A,Saviano M,De Simone G,Nastri F,Maglio O,Omote Y,Yamanaka Y,Yamada T

更新日期：2000-02-01 00:00:00

abstract：:The self-cleaving hepatitis delta virus (HDV) ribozyme is essential for the replication of HDV, a liver disease causing pathogen in humans. The catalytically critical nucleotide C75 of the ribozyme is buttressed by a trefoil turn pivoting around an extruded G76. In all available crystal structures, the conformation of...

journal_title：Biopolymers

authors： Sefcikova J,Krasovska MV,Spacková N,Sponer J,Walter NG

更新日期：2007-04-05 00:00:00

abstract：:In recent years, a revolution has occurred in the basic sciences, which exploits novel single molecule detection and manipulation tools to track and analyze biopolymers in unprecedented detail. A recent Gordon Research Conference style meeting, hosted by the University of Michigan, highlighted current status and futur...

journal_title：Biopolymers

authors： Walter NG,Meiners JC,Meyhofer E,Neubig RR,Sunahara RK,Perkins NC,Steel DG,Swanson JA

更新日期：2007-02-05 00:00:00

abstract：:Spontaneous cortical activity of single neurons is often either dismissed as noise, or is regarded as carrying no functional significance and hence is ignored. Our findings suggest that such concepts should be revised. We explored the coherent population activity of neuronal assemblies in primary sensory area in the a...

journal_title：Biopolymers

authors： Grinvald A,Arieli A,Tsodyks M,Kenet T

更新日期：2003-03-01 00:00:00

abstract：:In our continuing series of measurements of the complex index of refraction for representative samples of biological materials, we measured ovalbumin (egg albumin) over the spectral region from 0.130 (76,923 cm(-1)) to 2.50 microm (4000 cm(-1)). Films of ovalbumin suitable for optical analyses were prepared and measur...

journal_title：Biopolymers

authors： Arakawa ET,Tuminello PS,Khare BN,Milham ME

更新日期：2001-01-01 00:00:00

abstract：:Individual ethidium-stained DNA molecules, embedded in an agarose gel made with electrophoresis buffer (0.05 molar salt), are observed using a fluorescence microscope. In the first experiment, open circular 66 kilobase pair (kbp) plasmids, immobilized by agarose fibers threaded through their centers, display entropic ...

journal_title：Biopolymers

authors： Smith SB,Bendich AJ

更新日期：1990-07-01 00:00:00

abstract：:DNA sequences containing four types of analog nucleosides are described. All four are pyridine derivatives constructed as C-nucleosides so that they mimic the pyrimidine derivatives 2'-deoxyuridine, thymidine or 2'-deoxycytidine, but in all cases the analogs lack the corresponding O2-carbonyls that in duplex DNA are l...

journal_title：Biopolymers

authors： Sun Z,McLaughlin LW

更新日期：2007-10-05 00:00:00

abstract：:Different atomic point charge sets are obtained for the alpha R and C7,eq conformations of the alanine dipeptide by fitting the charges of each conformation to the respective ab initio electrostatic potential surfaces both individually and simultaneously, in both the united atom and the all-atom representations. Using...

journal_title：Biopolymers

authors： Resat H,Maye PV,Mezei M

更新日期：1997-01-01 00:00:00

abstract：:The general properties of hydroxyethylcellulose (HEC) grafted with 3-glycidoxypropyltrimethoxysilane (GPTMS) or 3-glycidoxypropylmethyldiethoxysilane (GPDMS) were studied for potential biomedical applications. The graft involved a Williamson reaction between the free hydroxyl function of HEC and the epoxy function of ...

journal_title：Biopolymers

authors： Bourges X,Weiss P,Coudreuse A,Daculsi G,Legeay G

更新日期：2002-04-05 00:00:00

abstract：:H-Pro-Pro-Asp-NH2 is a highly active and selective catalyst for asymmetric aldol reactions. Here, the versatility of H-Pro-Pro-Asp-NH2 has been further improved by immobilization on a solid support and functionalization with a short polyethylene glycol linker at the C-terminus. The development, synthesis, and the cata...

journal_title：Biopolymers

authors： Revell JD,Gantenbein D,Krattiger P,Wennemers H

更新日期：2006-01-01 00:00:00

abstract：:RNA and DNA molecules experience motions on a wide range of time scales, ranging from rapid localized motions to much slower collective motions of entire helical domains. The many functions of RNA in biology very often require this molecule to change its conformation in response to biological signals in the form of sm...

journal_title：Biopolymers

authors： Shajani Z,Varani G

更新日期：2007-08-05 00:00:00