Abraham Ulman , Jung F. Kang , Yitzhak Shnidman , Sheng Liao , Rainer Jordan , Gun-Young Choi , Julien Zaccaro , Allan S. Myerson , Miriam Rafailovich , Jonathan Sokolov , Cathy Fleischer
{"title":"Self-assembled monolayers of rigid thiols","authors":"Abraham Ulman , Jung F. Kang , Yitzhak Shnidman , Sheng Liao , Rainer Jordan , Gun-Young Choi , Julien Zaccaro , Allan S. Myerson , Miriam Rafailovich , Jonathan Sokolov , Cathy Fleischer","doi":"10.1016/S1389-0352(00)00013-1","DOIUrl":"10.1016/S1389-0352(00)00013-1","url":null,"abstract":"<div><p>The preparation, structure, properties and applications of self-assembled monolayers (SAMs) of rigid 4-mercaptobiphenyls are briefly reviewed. The rigid character of the biphenyl moiety results in a molecular dipole moment that affects both the adsorption kinetics<span> on gold surfaces, as well as the equilibrium structure of mixed SAMs. Due to repulsive intermolecular interaction, the Langmuir isotherm model does not fit the adsorption kinetics of these biphenyl thiols, and a new Ising model was developed to fit the kinetics data. The equilibrium structures of SAMs and mixed SAMs depend on the polarity of the solution from which they were assembled. Infrared spectroscopy suggests that biphenyl moieties in SAMs on gold have small tilt angles with respect to the surfaces normal. Wetting studies shows that surfaces of these SAMs are stable for months, thus providing stable model surfaces that can be engineered at the molecular level. Such molecular engineering is important for nucleation and growth studies. The morphology of glycine crystals grown on SAM surfaces depends on the structure of the nucleating glycine layer, which, in turn, depends on the H-bonding of these molecules with the SAM surface. Finally, the adhesion of PDMS cross-linked networks to SAM surfaces depends on the concentration of interfacial H-bonding. This non-linear relationship suggests that the polymeric nature of the elastomer results in a collective H-bonding effect.</span></p></div>","PeriodicalId":101090,"journal":{"name":"Reviews in Molecular Biotechnology","volume":"74 3","pages":"Pages 175-188"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1389-0352(00)00013-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21964413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W Knoll , C.W Frank , C Heibel , R Naumann , A Offenhäusser , J Rühe , E.K Schmidt , W.W Shen , A Sinner
{"title":"Functional tethered lipid bilayers","authors":"W Knoll , C.W Frank , C Heibel , R Naumann , A Offenhäusser , J Rühe , E.K Schmidt , W.W Shen , A Sinner","doi":"10.1016/S1389-0352(00)00012-X","DOIUrl":"10.1016/S1389-0352(00)00012-X","url":null,"abstract":"<div><p><span><span>Our strategy to provide the structural basis for the build-up of functional tethered membranes focuses on three approaches: the first one is based on the pre-organization of a monomolecular layer of a lipopolymer at the water/air interface which is then transferred to a solid support. Prior to deposition, the substrate is coated with a layer of benzophenone-derivatized silane molecules that allow for a stable covalent attachment by photo-cross-linking of some of the monomer units of the lipopolymer to the support. An alternative concept realizes a layer-by-layer deposition of the various structural elements: (1) the attachment layer with the reactive sites for the chemical stabilization; (2) a polymer ‘cushion’ prepared by adsorption and simultaneous or subsequent partial covalent binding to the reactive sites; and (3) a lipid monolayer transferred from the water/air interface, that contains a certain amount of lipids with reactive headgroups which, upon binding to the polymer tether, act as anchor lipids stabilizing the whole monolayer/cushion-composite. And finally, we build peptide-supported monolayers by first (self-) assembling </span>amino acid sequences of various lengths via a SH-group near their N-terminus onto Au substances and use then their COO</span><sup>−</sup><span>-terminus to chemically attach phosphatidyl-ethanolamine lipids to form a stable monolayer of lipid–peptide conjugates. All the individual preparation steps and the various resulting (multi-) layers are characterized by surface plasmon spectroscopy, X-ray and neutron-reflectometry, contact angle measurements, IR spectroscopy<span><span><span>, fluorescence microscopy<span><span>, scanning probe microscopies, as well as, electrochemical techniques. For all tethering systems, the final membranes' architecture is obtained by fusing lipid vesicles onto the lipid monolayer. Proteins can be incorporated by either fusing vesicles that are loaded with the respective receptors, pores, or </span>ion pumps<span> via a reconstitution procedure, or via a transfer directly from a micellar solution to the pre-formed lipid bilayer at the solid support by a dialysis step. Two structural/dynamical features of tethered membranes which are considered to be of particular functional relevance, i.e. the degree of water uptake and, hence, the degree of swelling of the polymer support, as well as the lateral mobility of the lipid molecules in the membrane, are tested by surface plasmon optics and by measurements of the </span></span></span>fluorescence recovery after photobleaching<span><span><span> (FRAP), respectively. The results confirm that the presented preparation protocols yield fluid bilayers that mimic certain relevant properties of </span>biological membranes. The functional characterization of tethered membranes, which is briefly summarized, is based on various electrochemical techniques, in particular, </span>impedance spectroscopy, </span></span>cyclic voltammet","PeriodicalId":101090,"journal":{"name":"Reviews in Molecular Biotechnology","volume":"74 3","pages":"Pages 137-158"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1389-0352(00)00012-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21964411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jaroslaw Majewski , Tonya L. Kuhl , Joyce Y. Wong , Gregory S. Smith
{"title":"X-ray and neutron surface scattering for studying lipid/polymer assemblies at the air–liquid and solid–liquid interfaces","authors":"Jaroslaw Majewski , Tonya L. Kuhl , Joyce Y. Wong , Gregory S. Smith","doi":"10.1016/S1389-0352(00)00011-8","DOIUrl":"10.1016/S1389-0352(00)00011-8","url":null,"abstract":"<div><p>Simple mono- and bilayers<span>, built of amphiphilic molecules and prepared at air–liquid or solid–liquid interfaces, can be used as models to study such effects as water penetration, hydrocarbon chain packing, and structural changes due to head group modification. In the paper, we will discuss neutron and X-ray reflectometry and grazing incidence X-ray diffraction techniques used to explore structures of such ultra-thin organic films in different environments. We will illustrate the use of these methods to characterize the morphologies of the following systems: (i) polyethylene glycol-modified distearoylphosphatidylethanolamine monolayers at air–liquid and solid–liquid interfaces; and (ii) assemblies of branched polyethyleneimine polymer and dimyristoylphophatidylcholine lipid at solid–liquid interfaces.</span></p></div>","PeriodicalId":101090,"journal":{"name":"Reviews in Molecular Biotechnology","volume":"74 3","pages":"Pages 207-231"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1389-0352(00)00011-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21964415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"New silk protein: modification of silk protein by gene engineering for production of biomaterials","authors":"Hajime Mori , Masuhiro Tsukada","doi":"10.1016/S1389-0352(00)00004-0","DOIUrl":"10.1016/S1389-0352(00)00004-0","url":null,"abstract":"<div><p><span><span>The interest in silk fibroin morphology and structure have increased due to its attractiveness for bio-related applications. Silk fibers have been used as sutures for a long time in the surgical field, due to the biocompatibility of silk fibroin fibers with human living tissue. In addition, it has been demonstrated that silk can be used as a substrate for </span>enzyme immobilization<span><span> in biosensors. A more complete understanding of silk structure would provide the possibility to further exploit silk fibroin for a wide range of new uses, such as the production of oxygen-permeable membranes and biocompatible materials. Silk fibroin-based membranes could be utilized as soft tissue compatible polymers. Baculovirus-mediated transgenesis of the </span>silkworm<span> allows specific alterations in a target sequence. Homologous recombination of a foreign gene downstream from a powerful promoter, such as the fibroin promoter, would allow the constitutive production of a useful protein in the silkworm and the modification of the character of silk protein. A chimeric protein consisted of fibroin and </span></span></span>green fluorescent protein was expressed under the control of fibroin in the posterior silk gland and the gene product was spun into the cocoon layer. This technique, gene targeting, will lead to the modification and enhancement of physicochemical properties of silk protein.</p></div>","PeriodicalId":101090,"journal":{"name":"Reviews in Molecular Biotechnology","volume":"74 2","pages":"Pages 95-103"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1389-0352(00)00004-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56527855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Strength and structure of spiders’ silks","authors":"Fritz Vollrath","doi":"10.1016/S1389-0352(00)00006-4","DOIUrl":"10.1016/S1389-0352(00)00006-4","url":null,"abstract":"<div><p>Spider silks are composite materials with often complex microstructures. They are spun from liquid crystalline dope using a complicated spinning mechanism which gives the animal considerable control. The material properties of finished silk are modified by the effects of water and other solvents, and spiders make use of this to produce fibres with specific qualities. The surprising sophistication of spider silks and spinning technologies makes it imperative for us to understand both material and manufacturing in nature before embarking on the commercialization of biotechnologically modified silk dope.</p></div>","PeriodicalId":101090,"journal":{"name":"Reviews in Molecular Biotechnology","volume":"74 2","pages":"Pages 67-83"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1389-0352(00)00006-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56527885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lessons from nature — protein fibers","authors":"Karl-Heinz Gührs , Klaus Weisshart , Frank Grosse","doi":"10.1016/S1389-0352(00)00007-6","DOIUrl":"10.1016/S1389-0352(00)00007-6","url":null,"abstract":"<div><p>Silks are protein fibers with remarkable mechanical properties. The discovery of the structural features that govern these properties is a challenge for biochemistry and structural biology. This review summarizes the results of the biochemistry of silk proteins as well as the knowledge of the molecular biology of the respective genes. In addition, an overview is presented on the efforts to produce recombinant silk proteins by biotechnological techniques.</p></div>","PeriodicalId":101090,"journal":{"name":"Reviews in Molecular Biotechnology","volume":"74 2","pages":"Pages 121-134"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1389-0352(00)00007-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56527898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Molecular biology of spider silk","authors":"Stefan Winkler, David L Kaplan","doi":"10.1016/S1389-0352(00)00005-2","DOIUrl":"10.1016/S1389-0352(00)00005-2","url":null,"abstract":"<div><p><span>Spider silks are an intriguing family of fibrous proteins due to their highly repetitive primary sequence, their solution properties and their assembly and processing into fibers with remarkable mechanical properties. Current research efforts aimed at understanding and manipulating genes encoding these proteins are helping to gain insight into the relationships between </span>protein sequence, protein assembly and macromolecular properties.</p></div>","PeriodicalId":101090,"journal":{"name":"Reviews in Molecular Biotechnology","volume":"74 2","pages":"Pages 85-93"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1389-0352(00)00005-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56527876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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