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Boonclarm D Sornwatana T Arthan D Kongsaeree P Svasti J 《Acta biochimica et biophysica Sinica》2006,38(8):563-570
An iridoid β-glucoside, namely plumieride coumarate glucoside, was isolated from the Plumeria obtusa (white frangipani) flower. A β-glucosidase, purified to homogeneity from P. obtusa, could hydrolyze plumieride coumarate glucoside to its corresponding β-O-coumarylplumieride. Plumeria β-glucosidase is a monomeric glycoprotein with a molecular weight of 60.6 kDa and an isoelectric point of 4.90. The purified β-glucosidase had an optimum pH of 5.5 for p-nitrophenol (pNP)-β-D-glucoside and for its natural substrate. The Km values for pNP-β-D-glucoside and Plumeria β-glucoside were 5.04±0.36 mM and 1.02±0.06 mM, respectively. The enzyme had higher hydrolytic activity towards pNP-β-D-fucoside than pNP-β-D-glucoside. No activity was found for other pNP-glycosides. Interestingly, the enzyme showed a high specificity for the glucosyl group attached to the C-7" position of the coumaryl moiety of plumieride coumarate glucoside. The enzyme showed poor hydrolysis of 4-methylumbelliferyl-β-glucoside and esculin, and did not hydrolyze alkyl-β-glucosides, glucobioses, cyanogenic-β-glucosides, steroid β-glucosides, nor other iridoid β-glucosides. In conclusion, the Plumeria β-glucosidase shows high specificity for its natural substrate, plumieride coumarate glucoside. 相似文献
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Thammasirirak S Ponkham P Preecharram S Khanchanuan R Phonyothee P Daduang S Srisomsap C Araki T Svasti J 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2006,143(2):209-217
Cation exchange column chromatography and gel filtration chromatography were used to purify four reptile lysozymes from egg white: SSTL A and SSTL B from soft shelled turtle (Trionyx sinensis), ASTL from Asiatic soft shelled turtle (Amyda cartilagenea) and GSTL from green sea turtle (Chelonia mydas). The molecular masses of the purified reptile lysozymes were estimated to be 14 kDa by SDS-PAGE. Enzyme activity of the four lysozymes could be confirmed by gel zymograms and showed charge differences on native-PAGE. SSTL A, SSTL B and ASTL had sharp pH optima of about pH 6.0, which contrasts with that of GSTL, which showed dual pH optima at about pH 6.0 and pH 8.0. The activities of the reptile lysozymes rapidly decreased within 30 min of incubation at 90 degrees C except for ASTL, which was more stable. Partial N-terminal amino acid sequencing and peptide mapping strongly suggested that the enzymes were C-type lysozymes. Interestingly, the mature SSTL lysozymes show an extra Gly residue at the N-terminus, which was previously found in soft-shelled turtle lysozyme. The reptile lysozymes showed lytic activity against several species of bacteria, such as Micrococcus luteus and Vibrio cholerae, but showed only weak activity to Pseudomonas aeruginosa and lacked activity towards Aeromonas hydrophila. 相似文献
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Ngiwsara Lukana Vatanavicharn Nithiwat Sawangareetrakul Phannee Liammongkolkul Somporn Ratanarak Pisanu Boonyawat Boonchai Srisomsap Chantragan Champattanachai Voraratt Ketudat-Cairns James Wasant Pornswan Svasti Jisnuson 《Molecular biology reports》2021,48(3):2063-2070
Molecular Biology Reports - Phenylketonuria (PKU) is an autosomal recessive amino acid metabolism disorder caused by variants in the gene encoding phenylalanine hydroxylase (PAH; EC1.14.16.1). This... 相似文献
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Improvement in the resolution of human sperm protamines by use of iodoacetamide as alkylating agent.
By use of the neutral alkylating agent iodo [14C1] acetamide instead of ethylene imine or iodoacetate, the resolution of human protamines on gel electrophoresis and ion-exchange chromatography has been improved. Using 20-cm gels, human protamines may be fractionated into seven bands, including the two chromatographically distinct forms of HP1 and a hitherto undetected component HP4. On ion-exchange chromatography, HP2 and the two forms of HP1 may be isolated in sufficient purity for sequence analysis. 相似文献