@article { ISI:000170577200041,
	title = {Catalysis by hen egg-white lysozyme proceeds via a covalent intermediate},
	journal = {NATURE},
	volume = {412},
	number = {6849},
	year = {2001},
	month = {AUG 23},
	pages = {835-838},
	abstract = {Hen egg-white lysozyme (HEWL) was the first enzyme to have its three-dimensional structure determined by X-ray diffraction techniques(1). A catalytic mechanism, featuring a long-lived oxo-carbenium-ion intermediate, was proposed on the basis of model-building studies(2). The {\textquoteleft}Phillips{\textquoteright} mechanism is widely held as the paradigm for the catalytic mechanism of beta -glycosidases that cleave glycosidic linkages with net retention of configuration of the anomeric centre. Studies with other retaining beta -glycosidases, however, provide strong evidence pointing to a common mechanism for these enzymes that involves a covalent glycosyl-enzyme intermediate, as previously postulated(3). Here we show, in three different cases using electrospray ionization mass spectrometry, a catalytically competent covalent glycosyl-enzyme intermediate during the catalytic cycle of HEWL. We also show the three-dimensional structure of this intermediate as determined by Xray diffraction. We formulate a general catalytic mechanism for all retaining beta -glycosidases that includes substrate distortion, formation of a covalent intermediate, and the electrophilic migration of C1 along the reaction coordinate.},
	issn = {0028-0836},
	doi = {10.1038/35090602},
	author = {Vocadlo, DJ and Davies, GJ and Laine, R and Withers, SG}
}
