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21.
The antibacterial factor from the body surface of the African giant snail, Achatina fulica Férussac, was isolated by DEAE-Toyopearl 650M ion exchange chromatography. The isolated preparation exhibited highly positive antibacterial activity both for the Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus and for the Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, but it lost such activity when heated at 75 degrees C for 5 min. The antibacterial factor of the snail mucus was a glycoprotein whose molecular weight (MW) was about 160,000. It was composed of two subunits of MW 70,000-80,000.  相似文献   
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Using fast atom bombardment (FAB) and tandem mass spectrometry (MS/MS), we examined 12 synthetic N-carbamoylamino acids (CAA) as tert-butyldimethylsilyl (TBDMS) derivatives. In FAB mass spectrometry and FAB MS/MS, spectra of protonated molecules for CAA provide specific cleavages involving the TBDMS carbamoyl moiety. The daughter scan spectrum of the parent ion indicated that it was useful for structural elucidation and differentiation of structural isomers of CAA. We have also identified each CAA separately in a mixture using a neutral loss scan for characteristic ions. In addition, we demonstrated that CAA in urine samples from patients with ornithine carbamoyl transferase deficiency gave collision-induced dissociation (CID) spectra which correspond well with CID spectra obtained using synthetically prepared CAA.  相似文献   
25.
This study tested the hypothesis that changes in photoperiod alter plasma catecholamine concentrations in the rhesus monkey during late gestation. Twelve chronically catheterized pregnant rhesus macaques were acclimated to a 12-h photoperiod (lights-on, 0700-1900 h). Under the control L:D cycle, blood samples were collected at 3-h intervals over 24 h for catecholamine analysis. Plasma concentrations (mean +/- SEM, pg/ml) ranged from 678 +/- 90 to 928 +/- 142 for norepinephrine; 230 +/- 22 to 631 +/- 141 for epinephrine; and 282 +/- 70 to 1090 +/- 362 for dopamine. A diurnal rhythm was observed in epinephrine with peak concentrations during lights-on (0900-1800 h; p less than 0.05, compared to lights-off). After the first sampling protocol, the animals were divided equally between two groups: phase shift, in which lights-on was shifted 11 h (2000-0800 h) and constant light, with lights on continuously. After the phase shift, a parallel shift in the plasma epinephrine rhythm was noted, with peak levels observed between 2200 and 0700 h (p less than 0.05). Constant light abolished the rhythm in epinephrine, with an overall reduction in mean basal levels of all three catecholamines. Daily melatonin infusions (0.2 micrograms/kg/h, 1900-0630 h) under constant light failed to restore the epinephrine rhythm or to return basal catecholamine concentrations to control photoperiod levels. These data suggest that photoperiod entrains the rhythm in epinephrine secretion, but the rhythm is ablated under constant conditions. Further, melatonin does not appear to play a role in the regulation of catecholamine secretion in the pregnant rhesus macaque.  相似文献   
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Four major sialo compounds, termed GP-M1, GP-D1, GP-D2, and GP-D3 have been isolated from the urine of a novel glycoprotein storage disorder patient with angiokeratoma corporis diffusum which was discovered by Kanzaki et al. (Kanzaki, T., Yokota, M., Mizuno, N., Matsumoto, Y., and Hirabayashi, Y. (1989) Lancet April 22, 875-877). Based on the results of fast atom bombardment mass spectrometry, methylation analysis, and proton nuclear magnetic resonance spectroscopy, their chemical structures were concluded to be: (formula; see text) The yields of GP-M1, GP-D1, GP-D2, and GP-D3 were approximately 15, 6, 50, and 5 mg/liter of urine, respectively. The most major compound GP-D2, was further purified into single molecular species, threonine and serine type, by reversed phase high performance liquid chromatography. NMR analysis of the two purified compounds with single molecular species showed that the chemical shifts of anomeric protons of GalNAc were significantly different between threonine- and serine-linked GalNAc. Neither mannose-containing glycopeptides nor glycosphingolipids were excreted in the patient urine. From these results, this disease is thought to be caused by the deficiency of a lysosomal enzyme(s) acting on O-linked glycan chains.  相似文献   
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Spinasterone and 22,23-dihydrospinasterone were isolated from the seed oil of Thea sinensis which contains spinasterol and 22,23-dihydrospinasterol as the two major sterol constituents.  相似文献   
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Two new esterase polymorphisms (Es-7 and Es-8) were identified in the testis homogenate of laboratory rats, Rattus norvegicus, by using discontinuous gradient polyacrylamide gel electrophoresis. Es-7 expressed two phenotypes: ES-7A (fast) and ES-7B (slow). Es-8, which migrated in the cathodal region rather than the ES-7 region, also expressed two phenotypes: ES-8A (fast) and ES-8B (slow). Linkage tests among Es-2, Es-7, and Es-8 were made from backcross progeny of the mating (LEJ/Hkm × T/Hok)F1 × LEJ/Hkm. One recombinant in 51 progeny tested was observed between Es-2 and Es-7; however, recombination between Es-2 and Es-8 was not observed in the same progeny. In addition, we show that the esterase polymorphisms of Es-5 in liver homogenate and Es-3 in small intestine homogenate are identical.  相似文献   
29.
The optimal conditions for the activation of Sepharose by epichlorohydrin and subsequent immobilization of ligands were investigated. Under the optimal conditions for activation, namely, 30% Sepharose-5% epichlorohydrin-0.4 M NaOH, 40 degrees C, 2 h, the maximum amount of epoxy group was introduced into Sepharose with low cross-linking. The absorbents obtained by using N-acetyl-D-glucosamine, tri-N-acetylchitotriose, and glycoprotein as a ligand exhibited no nonspecific adsorption and good permeability for the high molecular substance to be purified, and were stable in an alkaline solution. Solanum tuberosum agglutinin was specifically adsorbed on a tri-N-acetylchitotriose-Sepharose column and was quantitatively recovered by elution with 0.2 M ammonia solution. Furthermore, the column could be repeatedly used under these conditions without reduction of its capacity.  相似文献   
30.
Escherichia coli strains harboring Rtsl were found to excrete extracellular deoxyribonuclease. The DNase activity was greater in cells with pTW2, a mutant from Rtsl.  相似文献   
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