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Showing papers in "International Journal of Biological Macromolecules in 1986"


Journal ArticleDOI
TL;DR: In this article, the role of sodium iodide as an electrostatic charges screening salt is discussed, and the reaction was performed in several steps to obtain derivatives of chitosan at various degrees of quaternization with a limit value near 64%.

217 citations


Journal ArticleDOI
TL;DR: In this article, high molecular weight alginates having a variety of initial composition and sequential structures were modified with a mannuronan-C-5 epimerase from Azotobacter vinelandii to yield polymers with a high content of guluronic acid and, hence, an enhanced ability to form gels with calcium ions.

130 citations


Journal ArticleDOI
TL;DR: In this paper, the shear piezoelectricity was observed in oriented films of poly-β-hydroxybutyrate (PHB) and copolymers of β-hydroxbutyrates (HB) and βhydroxyvalerate (HV) at a frequency of 10 Hz over a temperature range from −150° to +150°C.

116 citations


Journal ArticleDOI
TL;DR: It is suggested that the hydroxyl groups of C-3 and C-6 positions are equally substituted with the phosphate group, which means that chitin phosphates (P-chitins) are easily soluble in water independent of DS, while DA-ch itins of high DS are insoluble in water owing to the amphoteric property, while those of low DS are water soluble.

111 citations


Journal ArticleDOI
TL;DR: In this article, the interaction of univalent and divalent counter-ions with fucoidan was investigated by viscometry and polarimetry, and by measuring the counter-ion activites and conductance coefficients in salt-free solutions.

106 citations


Journal ArticleDOI
Barry V. McCleary1
TL;DR: In this article, the authors discuss the use of enzymes in the modification of the functional properties of plant polysaccharides both in vivo and in vitro, depending on the specific enzyme or enzyme mixture employed and on the particular industrial requirement.

106 citations


Journal ArticleDOI
TL;DR: Electron microscopy and turbidimetry have been used to show that the reconstitution of native-type banded fibrils from a solution of acetic acid-soluble collagen (with intact telepeptides) can proceed by different assembly pathways, depending on the initiating procedure used to bring the collagen from a dissolved to a precipitating condition.

99 citations


Journal ArticleDOI
TL;DR: Recombinant plasmids pij3040 and pIJ3041 containing overlapping fragments of the genome of wild type Xanthomonas campestris pv.c.campestris restored the production of extracellularpolysaccharide to non-slimy mutants and the EPS-deficient mutants retained pathogenicity in a seedlin bioassay.

95 citations


Journal ArticleDOI
TL;DR: In this article, the salinity dependence of xanthan conformation is analyzed on the basis of Yamakawa's theory for a wormlike chain model with a total persistence length comprising a structural part, which is found to assume different values depending on the nature of the secondary structure (ordered or not), and an electrostatic part which is dependent on the ionic strength.

95 citations


Journal ArticleDOI
TL;DR: In this paper, the degree of N-acetylation of chitosan was determined based on ultraviolet (u.v.) absorbance at 220 nm of acetamide groups.

82 citations


Journal ArticleDOI
TL;DR: In this paper, the linear dimensions of human α-lactalbumin molecules in the native "molten globule" and unfolded states were compared using quasielastic light scattering.

Journal ArticleDOI
TL;DR: This article showed that xanthan molecules at room temperature may assume at least three different conformations in 0.1 m NaCl aqueous solutions in which the local structure is ordered.

Journal ArticleDOI
TL;DR: In this article, the authors used electron microscopic data together with measurements of intrinsic viscosity to estimate the average molecular weight of sonicated and fractionated xanthan of type Kelzan XCD.

Journal ArticleDOI
TL;DR: The oxidative sulphitolysis rather than the previously used S-carboxymethylation is the method of choice to prepare α-keratin derivatives suitable for assembly experiments and once the protecting S-sulpho group is removed by 2-mercaptoethanol in vitro filaments formation can be induced.

Journal ArticleDOI
TL;DR: In this article, the authors obtained X-ray diffraction patterns of high quality from oriented polycrystalline fibres of the extracellular microbial polysaccharide gellan gum.

Journal ArticleDOI
TL;DR: A series of N-acetylglucosamine oligomers with DP 1 to 10 has been studied by circular dichroism and the anomeric α-β equilibrium composition is determined for the monomer.

Journal ArticleDOI
TL;DR: In this paper, high-angle diffuse X-ray scattering was applied for the comparison of intramolecular packing of human α-lactalbumin in native and "molten globule" (acid) states.

Journal ArticleDOI
TL;DR: In this paper, Chitosan (acetylations degree, 3%) was dissolved with alpha-keto glutaric acid and with 5 keto-d -gluconic acid to yield the respective ketimines.

Journal ArticleDOI
TL;DR: In this article, the generalized packing model was used to calculate the water content within the collagen fibrils of rat bone matrix, rat tail tendon fibres, and fully mineralized cow tibia.

Journal ArticleDOI
TL;DR: The weight average molecular weight (Mw) of sodium alginates was determined using photon correlation spectroscopy rather than boundary spreading in the analytical ultracentrifuge to determine the translational diffusion coefficients as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this paper, Fourier transform infrared (F.t.m.i.r.) spectra were obtained for Na +, K + and Cs + forms of iota and kappa carrageenan in water and D 2 O.

Journal ArticleDOI
TL;DR: In this paper, the polysaccharides produced by growing and non-growing bacteria have been isolated, purified and determined to contain glucose, galactose, pyruvic acid, acetic acid, and succinic acid.

Journal ArticleDOI
TL;DR: In this paper, the effects of glycosidic linkage geometry on polysaccharide shape and structure is discussed together with the effect of changes in the geometry of the monomer units.

Journal ArticleDOI
TL;DR: In this paper, the crystallographic structure of O-β-d -mannopyranosyl is reported and the data, together with those of mannobiase, have been used to model, on a computer, the mannan and glucomannan polysaccharide chains.

Journal ArticleDOI
TL;DR: The time dependence of turbidity increases as well as changes inmolecular weight associated with type I collagen self assembly were analysed in terms of classical nucleation and growth kinetics as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, the order-disorder transition temperatures of the polysaccharides succinoglycan and xanthan are strongly influenced by the salts present in solution, thus decreasing the stability of the polymer and increasing its susceptibility to acid catalysed degradation.

Journal ArticleDOI
TL;DR: In the presence of alcohol, the α-helix structure of κ-casein was less sensitive to the addition of methanol, ethanol, propan-1-ol and 2,2,2-trifluoroethanol as discussed by the authors.

Journal ArticleDOI
TL;DR: Variations in the molar proportions of these products were observed, but, if one considers the fractions of molecular weights ranging from 13 000 to 34 000, these ratios are roughly the same, indicating that, in spite of the molecular weight variation, the structural pattern is the same for almost all the polymeric chains.

Journal ArticleDOI
TL;DR: The results demonstrate that the procollagen propeptides do not alter the molecular flexibility of the helical portion of the molecule but do appear to limit association of collagen molecules and may play a role in modulating the early stages of collagen fibrillogenesis.

Journal ArticleDOI
TL;DR: In this article, the authors investigate and compare the properties of families of polysaccharides in which individual members of the group show small naturally arising modifications to the chemical structure and show the effects of changes in the polymer backbone, polymer side chains and non-carbohydrate substituents on polymer functionality.