Showing papers in "International Journal of Biological Macromolecules in 1999"

TL;DR: Several types of silks and silk protein coding genes have been characterized from orb-web weaving spiders, and correlations are drawn between an alanine-rich 'crystalline module' and tensile strength and between a proline-containing 'elasticity module" and extensibility.

TL;DR: In this article, a chitosan:glutaraldehyde molar proportion of 1:20 was established for a CHITOSAN:GLUTARaldehyde mixture.

TL;DR: In this article, the development of medical applications for polyhydroxyalkanoates (PHAs), a class of natural polymers with a wide range of thermoplastic properties, is described.

TL;DR: Electrostatic interactions and hydrogen bonds are found to be the dominating forces among macromolecules within the biofilm.

TL;DR: The direction, in which research should proceed, in order to increase knowledge on biosynthesis of PHAs and to utilize this knowledge for the development of technically and economically feasible processes for the production of these polyesters will be outlined.

TL;DR: The mechanical characteristics of dragline silks collected from a range of spiders drawn from the Argiopidae, Tetragnathidae, Theridiidae and Pisauridae displayed significant inter- and intraspecific differences, suggesting differences in basic silk properties.

TL;DR: Results suggest that acetate has the maximum molecular volume above which the film strength decreases very rapidly, which is essentially governed by the volume of thecounter ion and not by the interactions between this counter ion and the macromolecule.

TL;DR: Reexamination of the crystal structure of silk (Bombyx mori) was carried out by X-ray diffraction method and the molecular conformation is essentially the same pleated sheet structure as Marsh, Corey and Pauling proposed.

TL;DR: It seems that the spider is able to induce rapid and temporary adaptations of silk properties, and an argument can be made that silk is optimised for a wide range of conditions rather than maximised for strength or toughness.

TL;DR: Various bacterial strains, either wild-type or recombinant, and new fermentation strategies were developed for the production of P(3HB) with high concentration and productivity, to reduce the cost of carbon substrate and to produce biodegradable polymers.

TL;DR: A model is proposed which follows the conception of the particles, their growth, physical properties and stability, and which investigates the differences in such processes as a result of shearing during gelation.

TL;DR: The orientation distribution of the polymer chains of the crystalline fraction along the fiber axis was found to be about 23 degrees full-width at half maximum (fwhm) and the azimuthal spread of the short-range order fraction was about 86 degrees fwhm.

TL;DR: The authors' observations on the major ampullate gland of the spider Nephila edulis indicate that the exceptionally tough and strong core and coat composite structure of the dragline thread is formed by the co-drawing of two feedstocks through a single die.

TL;DR: End-group analysis by 31P NMR of polymer derivatized with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane revealed that all these compounds were covalently linked to P(3HB) at the carboxyl terminus, implying that chain transfer to glycerol is a random transesterification and that PHA synthase does not catalyse chain transfer.

TL;DR: This study focused on the identification of sorption mechanisms by means of several analytical procedures such as infra-red and reflectance spectrophotometries and CP-MAS 13C NMR analyses, showing that the carbon atoms supporting the amino sites are not the only atoms affected by molybdate ion sorption.

TL;DR: The granular immobilized lipase derived from Candida antartica showed extremely efficient catalysis in the polymerization of epsilon-caprolactone and the enzymatic polymerizability of lactones was quantitatively evaluated by Michaelis-Menten kinetics.

TL;DR: The extent of degradation of silk fibroin was assessed by measuring the intrinsic viscosity and determining the amino acid composition of silk after regeneration with an aqueous methanol solution, which was effective in removing the solvent and coagulating silk.

TL;DR: It is found that slightly acidic conditions in the solution from which the foam was generated favor the formation of silk II while neutral to slightly basic solutions favor silk I formation, and the first single crystal electron diffraction patterns of silk I are reported.

TL;DR: The semi-empirical approach was used to obtain the three coordinates of a solubility parameter in terms of: a dispersion part, a polar part and a hydrogen bonding part for polar polymers such as poly(3-hydroxyalkanoates), P(3HA).

TL;DR: Results suggested that intracellular acetyl phosphate concentration could be controlled, depending on C-N balance and intrace cellular acetyl-CoA concentration.

TL;DR: It is proposed that the diverse silk-producing systems of the araneoid spiders evolved through intra-organ competition and that taxon-specific differences in the composition of silks drawn from homologous glands may reflect limited or fluctuating amino acid availability.

TL;DR: This manuscript reviews work from the laboratory that addresses the orientation, secondary structure, wet-spinning, and molecular basis for supercontraction of spider silk and sets forth several molecular-level hypotheses concerningsupercontraction.

TL;DR: The genes encoding the polyhydroxyalkanoate (PHA) biosynthetic pathway in Ralstonia eutropha were engineered for plant plastid targeting and expressed using leaf (e35S) or seed-specific (7s) promoters in Arabidopsis and Brassica.

TL;DR: The consensus repeat sequence found in the dragline silk from the spider, Nephila clavipes, was redesigned to incorporate a redox trigger flanking the beta-sheet forming polyalanine sequences to explore the self-assembly of fibrous proteins such as silks.

TL;DR: Histology confirmed the heterogeneous degradation mechanism introduced nearly 10 years ago from in vitro investigations of homemade implants having simpler geometry and the effects of the initiator system used to polymerize the lactide monomer on the properties of injection molded interference screws was investigated.

TL;DR: There is a close relationship between conformation of beta-lactoglobulin in solution and its capacity to form a gel for the first time, and it is suggested that by controlling the extent of intermolecular beta-structure of the protein in solution, it is possible to modify the ability of protein to formA gel and as a consequence to control the properties of gels.

TL;DR: The galactomannans from the seeds of Caesalpinia pulcherrima and Cassia javanica were extracted from the milled seeds in water at room temperature and showed the behaviour of systems with predominant entanglement networks in the region between the terminal and plateau zones of frequency response.

TL;DR: The orientation of the fibroin chain axis in the plane of the interfacial film for uncompressed samples is consistent with the amphiphilic behavior previously postulated to drive the formation of the threefold helical silk III conformation.

TL;DR: The polymorphic structures of silk fibroins in the solid state were examined on the basis of a quantitative relationship between the 13C chemical shift and local structure in proteins to determine their 13C isotropic NMR chemical shifts.

TL;DR: Results obtained in the present study clearly indicate that macrophages and, to a lesser degree, osteoblasts have the ability to take up (phagocytose) PHB-P.