Catalytic versatility of Bacillus pumilus beta-xylosidase: glycosyl transfer and hydrolysis promoted with alpha- and beta-D-xylosyl fluoride.
Catalytic versatility of Bacillus pumilus beta-xylosidase: glycosyl transfer and hydrolysis promoted with alpha- and beta-D-xylosyl fluoride.
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短小芽孢杆菌β-木糖苷酶的催化多功能性：α-和β-D-木糖基氟化物促进糖基转移和水解。
DOI：
10.1021/bi00385a009
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发表时间：
1987
期刊：
影响因子：
2.9
通讯作者：
Hehre,EJ
中科院分区：
文献类型：
--
作者：
Kasumi,T;Tsumuraya,Y;Brewer,CF;Kersters-Hilderson,H;Claeyssens,M;Hehre,EJ
Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461, and Laboratory of Biochemistry, State University of Ghent, B-9000, Ghent, Belgium Received October 28, 1986; Revised Manuscript Received February 5, 1987 abstract: Bacillus pumilus/3-xylosidase, an enzyme considered restricted to hydrolyzing a narrow range of/3-D-xylosidic substrates with inversion of configuration, was found to catalyze different stereochemical, essentially irreversible, glycosylation reactions with a-and/3-D-xylopyranosylfluoride. The enzyme promoted the hydrolysis of/3-D-xylopyranosyl fluoride at a high rate, V= 6.25 µ min'1 mg'1 at0 C, in a reaction that obeyed Michaelis-Menten kinetics. In contrast, its action upon-D-xylopyranosyl fluoride was slow and characterized by an unusual relation between the rate of fluoride release and the substrateconcentration, suggesting the possible need for two substrate molecules to be bound at the active center in order for reaction to occur. Moreover, NMR spectra of a digest of-D-xylosyl fluoride showed the substrate to be specifically converted to-D-xylose by the enzyme. The observed retention of configuration is not consistent with direct hydrolysis by this “inverting” enzyme but is strongly indicative of the occurrence of two successive inverting reactions: xylosyl transferfrom-D-xylosyl fluoride to form a/3-D-xylosidic product, followed by hydrolysis of the latter to produce-D-xylose. The transient intermediate product formed enzymically from aD-xylosyl fluoride inthe presence of [14C] xylose was isolated and shown by its specific radioactivity and NMR spectrum as well as by methylation and enzymic analyses to be 4-0-/3-D-xylopyranosyl-D-xylopyranose containing one [14C] xylose residue. The results are related to our earlier findings with/3-amylase, glycoamylase, glucodextranase, and trehalase, which also had appeared to be strictly limited to catalyzing the hydrolysis of glycosidic substrates with inversion but which also were found to have functionally flexible catalytic groups capable of catalyzing nonhydrolyticglycosylation reactions by mechanisms other than for hydrolysis. e study of enzymic glycosylationreactions catalyzed without glycosidicbond cleavage has in recent years emerged as a powerful approach providing a much altered understanding of the catalytic and mechanistic capabilities of gly-cosylases. That is, through the use of glycosyl fluorides and enolic glycosyl substrates, various well-known glycoside hydrolases and glycosyltransferases have been found to have functionally flexible catalytic groups and the ability to promote glycosylation reactions with different substrates by different mechanisms (Hehre et al., 1977, 1979, 1980, 1982, 1986; Lehmann & Zieger, 1977; Kitahata et al., 1980; Schlessel-mann et al., 1982; Lehmann & Schlesselmann, 1983; Tsu-muraya et al., 1984a; Kanda et al., 1986; Kasumi et al., 1986). Studies with such truncated glycosyl substrateshave, for ex-ample, revealed the catalytic versatility of four well-known “inverting glycoside hydrolases”(/3-amylase, glucoamylase, f This study was supported by US Public Health Service Research Grant GM-25478 (to EJH) from the National Institute for General Medical Sciences. CFB was supported by Research Grant CA-16054 and by Core Research Grant P30-CA-13330 from the National Cancer Institute, National Institutes of Health.* Address correspondence to this author.* Albert EinsteinCollege of Medicine. S Research Associate in Microbiology and Immunology, Albert Ein-stein College of Medicine, on leave from the National Food Research Institute, Tsukuba, Ibaraki, Japan. 11 Research Associate …
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（bearbeitet von Almuth Klemer、Maria Nolte、Hans Nordiek、Leo Tork 和 Hans Westermann）。
DOI：
10.1002/cber.19570900834
发表时间：
1957
期刊：
Chemische Berichte
影响因子：
--
作者：
F. Micheel
通讯作者：
F. Micheel
对特定氟化碳水化合物的研究。
影响因子：
1.1
作者：
L. D. Hall;J. Manville;N. Bhacca
通讯作者：
N. Bhacca
来自短小芽孢杆菌的β-D-木糖苷酶。
DOI：
10.1016/0005-2795(75)90112-9
发表时间：
1975
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
M. Claeyssens;E. Saman;H. Kersters;C. de Bruyne
通讯作者：
C. de Bruyne
在脱氢酶催化的反应中，过渡态结构随核苷酸的变化而变化。
影响因子：
2.9
作者：
Scharschmidt,M;Fisher,MA;Cleland,WW
通讯作者：
Cleland,WW
2,3,4-三-O-苯甲酰基-β-d-吡喃木糖基氟和 2,3,4-三-O-乙酰基-β-d-吡喃木糖基氟的信息在 Kristall 中
DOI：
10.1107/s0567740879008505
发表时间：
1979
期刊：
Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry
影响因子：
--
作者：
G. Kothe;P. Luger;H. Paulsen
通讯作者：
H. Paulsen