(n.) A white amorphous horny substance forming the harder part of the outer integument of insects, crustacea, and various other invertebrates; entomolin.
Example Sentences:
(1) The effect of O-(carboxymethyl)chitins (CM-chitins) on the activation of mouse-peritoneal macrophages in vivo and their mitogenic activity on mouse spleen-cells were investigated.
(2) The pH activity profile, cofactor requirements, and kinetic parameters of the endogenously activated chitin synthase were identical to those of the trypsin-activated enzyme in protoplast membranes.
(3) Results obtained from isotopic dilution experiments are consistent with the operation of the chitin pathway as it has been established in fungal preparations.
(4) The significance of these results is discussed in connection with the mechanism of chitin synthesis and cell wall morphogenesis in S. cerevisiae.
(5) Here we show that the nodulation genes of this bacterium determine the production of a large family of Nod-factors which are N-acylated chitin pentamers carrying a variety of substituents.
(6) In a permeabilized-cell assay, Oct-Gln-UPOC had a 10-fold-lower inhibitory activity toward chitin synthetase than did the Oct-Lys-UPOC analog.
(7) The preparation yielded an apparent Km of 3.9 mg chitin ml-1 [17.6 mM-N-acetylglucosamine (GlcNAc) equivalents] and V of 2.3 nmol GlcNAc formed min-1 (mg protein)-1.
(8) In the case of the [14C]chitin synthesized, which does not show inhibition by alpha factor, the lowering of the specific activity of the precursor is exactly compensated for by an increased rate of chitin synthesis caused by alpha factor.
(9) Chitin derivatives are also used in things like contact lens, surgical stitches and artificial skin.
(10) The inhibitor was effective against crude or purified (chitosome) preparations of chitin synthetase.
(11) After 3 h incubation with tioconazole, 1 microgram ml-1, the incorporation of the radiolabelled glucose into chitin of intact cells and regenerating spheroplasts of C. albicans was inhibited by 43% and 30%, respectively.
(12) Electron microscopy has revealed that chitin from a representative selection of insect orders (plus one crustacean and one arachnid) is localized in crystallites about 2.8 nm across.
(13) When dividing cells of Saccharomyces cerevisiae were exposed to the polysaccharide-binding dye Congo red, the walls and septa became sites of chitin accumulation.
(14) Partially O-hydroxyethylated chitin (glycol chitin) was used as a substrate in the purification and characterization of this enzyme.
(15) In view of the small molecular size and high lipid solubility of methyl mercury and the lipophilic properties of the chitin-protein exoskeleton of the lobster, it is likely that significant uptake directly from the water as well as storage of absorbed methyl mercury occurred in the tail region.
(16) This confirmed that S. pombe cell wall is devoid of chitin.
(17) Adjuvant activity of chitin derivatives was examined in guinea-pigs and mice.
(18) DFB inhibits chitin synthesis and growth of imaginal epidermis in insects and suppresses melanogenesis and uptake of nucleosides in mouse melanoma cells, but the means of cell growth regulation and the role of metabolism of DFB in such regulation have not been established.
(19) These microfibers have a diameter of 80 A and may consist of chitin crystallites surrounded by a matrix coat.
(20) Chemical analysis of adult females of Onchocerca gibsoni gave estimated chitin contents of 200-500 micrograms (g dry weight)-1.
Lignin
Definition:
(n.) A substance characterizing wood cells and differing from cellulose in its conduct with certain chemical reagents.
Example Sentences:
(1) The manganese peroxidase (MnP), from the lignin-degrading fungus Phanerochaete chrysosporium, an H2O2-dependent heme enzyme, oxidizes a variety of organic compounds but only in the presence of Mn(II).
(2) 2-Chloro-1,4-dimethoxybenzene (IV) is oxidized by lignin peroxidase to generate 2,5-dimethoxy-1,4-benzoquinone (V), which is reduced to 2,5-dimethoxy-1,4-hydroquinone (VI).
(3) Increased numbers of fungi were detected only in the variant with AS-lignin at the end of the incubation.
(4) The molecular weight distribution of the dioxane-soluble lignin remained constant during degradation, but that of the water-soluble fraction changed to higher molecular weights.
(5) The experiments were performed with veratryl alcohol and a dimeric lignin model compound.
(6) The hydrolytic products of lignins, humic acids and industrial waste including hydroquinone, catechol, resorcinol, pyrogallol and 1,2,4-benzenetriol are widely distributed in water sources.
(7) Apparent digestibilities of DM, OM, CP, neutral detergent solubles and permanganate lignin were higher (P less than .01) and digestibilities of NDF and ADF, hemicellulose and cellulose were lower (P less than .01) for steers consuming alfalfa compared to orchardgrass silage.
(8) This study compared the dietary fiber (DF), neutral detergent fiber (NDF), cellulose, hemicellulose, lignin, and pectin content of selected fruits and vegetables.
(9) In the second pilot experiment, Phanerochaete chrysosporium and Chaetomium globosum, which are known for their ability to degrade lignin, were each incubated with wood dusts in a mixture of physiological saline and nutrient broth for either 3 or 30 days.
(10) Furthermore, oxidized lignin peroxidase is clearly a stronger oxidant than oxidized HRP or laccase.
(11) Goats selected diets 4% higher (P less than .1) in neutral detergent fiber on the control pastures than on the treated pastures; otherwise, diets selected by the goats on the various pastures were similar in terms of crude protein, lignin and in vitro organic matter digestibility.
(12) The concentration of oxalate in these cultures decreased during the period in which maximum lignin peroxidase activity (veratryl alcohol oxidation) was detected.
(13) In this study dosages of psyllium seed husk or lignin acceptable to patients with gallstones do not appear to alter the relative amounts of cholesterol, or individual bile acids in the bile.
(14) Natural lignocelluloses containing 14C primarily in their lignin components were prepared by feeding plants uniformly labeled L-[14C]phenylalanine through their cut stems.
(15) The ability of selected bacterial strains and consortia to mineralize degradation intermediates produced by Phanerochaete chrysosporium from 14C-labeled synthetic lignins was studied.
(16) Recombinant Phanerochaete chrysosporium lignin peroxidase isozyme H2 (pI 4.4) was produced in insect cells infected with a genetically engineered baculovirus containing a copy of the cDNA clone lambda ML-6.
(17) Lignin peroxidase also hydroxylated 1-(4'-ethoxy-3'-methoxyphenyl)propane II at the alpha-position to yield 1-(4'-ethoxy-3'-methoxyphenyl)-1-hydroxypropane VI under anaerobic conditions in the presence of mCPBA.
(18) Veratryl alcohol acts as a third substrate (with H2O2 and the azo dye) in the lignin peroxidase cycle during oxidations of azo dyes.
(19) The fungal fractions identified as cellulose and lignin varied widely with substrate.
(20) The oxidation of coniferyl alcohol (CA), a lignin precursor, by cell wall peroxidases may take place at the expense of indole-3-acetic acid (IAA) and O2, and in the absence of H2O2.