P-Glycosidase

Digestion of lactose is facilitated by the p glycosidase lactase A deficiency of this enzyme makes it difficult to digest lactose and causes abdominal discomfort Lactose intolerance is a genetic trait it is treatable through over the counter formulations of lac tase and by limiting the amount of milk m the diet... 

Glueosidase Clostridia, Eubacteria Cleavage of P-glycosidases of alcohols and phenols... 

R. W. Franck, The mechanism of p-glycosidases A reassessment of some seminal papers, Bioorg. Chem., 20 (1992) 77-88. 

P-Glycosidase and [5-galactosidase Synthesis of alkyl-b-glucosides in acetate buffer/l-hexanol or 1-octanol [67]... 

A. Trincone, E. Pagnotta, M. Rossi, M. Mazzone, and M. Moracci, Enzymatic synthesis of 2-deoxy-P-glucosides and stereochemistry of P-glycosidase from Sulfolobus solfataricus on glucal, Tetrahedron Asymmetry, 12 (2001) 2783-2787. 

Moracci, M., Capalbo, L., Ciaramella, M., and Rossi, M. (1996) Identification of two glutamic acid residues essential for catalysis in the p-glycosidase from the thermoacidophilic archaeon Sulfolobus solfataricus. Protein Eng. 12, 1191-1195. 

Moracci, M., Ciaramella, M., Nucci, R., Pearl, L.H., Sanderson, I., Trincone, A. and Rossi, M. (1994) Thermostable p-glycosidase from Sulfolobus solfataricus. Biocatalysis, 11, 89-103. 

Perugino, G., Falcicchio, P., Corsaro, M.M., Matsui, I., Parrilli, M., Rossi, M., and Moracci, M., (2006) Preparation of a glycosynthase from the P-glycosidase of the hyperthermophilic Archaeon Pyrococcus horikoshii. Biocat, Biotrans., 24, 23-29... 

Castanospermine is a polyhydroxylated alkaloid found in the plant Castanospermum australe.1 Its ability to function as a selective inhibitor of a and p glycosidases has made it the focal point of much synthetic activity in recent years.2 One particularly elegant synthesis of ( + )-castanospermine is that of Pandit and Overkleeft.3 It features a remarkable intramolecular olefin metathesis reaction for indolizidine ring assembly. We now analyse this interesting route, which showcases many important reagents and reactions used in contemporary organic synthesis. 

Changes in the conformation of the substrate required by ALPH during the catalytic turnover of a retaining p-glycosidase... 

The dependences, such as Eq. 2.47, are known as compensation effect, and coefficient (3C is denoted as isokinetic temperature at which all reactions of given series have the same rate constant. An example of compensation effect for for catalytic rate constant of the Sulfolobus solfataricus p-glycosidase reaction with different substrates is shown in Fig. 2.19. Similar relationships were reported for many other prosesses, involving the binding ligands to hemoglobin, the oxidation of alcohols by catalase, the hydroxylation of substrates by cytochrome c, etc. 

Biochemical and biophysical aspects of hyperthermophilic enzymes are as wide-ranging as all correspondent aspects of mesophilic enzymes but also include specific peculiarities. In this section some specific features of one of the typical hyperthermophylic enzymes, p-glycosidase Sulfolobus solfataricus, will be considered. 

P-glycosidase from the hyperthermophylic archaeon Sulfolobus solfataricus and its recombinants appear to be convenient objects for studying the relationship between intramolecular dynamics and enzyme activity (Nucci et al., 1993 Moracci et al., 1996 D Auria et al., 1998, 1999 Bismuto et al., 1999). The enzyme is barely active up to... 

The following peculiarities of the hyperthermostable P-glycosidase, which are different from that for proteins from mesophylic micro-organisms, were revealed in the results of the spin labelling experiments. 

Figure 4.5. Left side. Temperature dependence of the bimodal lifetime distribution parameters of Sulfolobus solfataricus (3-glycosidase. Long-lifetime component (squares) short lifetime component (circles). Right upper side W3/4H dependence on temperature thermal denaturation of Sulfolobus solfataricus p-glycosidase at pD 7.4 (continuous line) and pD 10.0 (dashed line). The lines were obtained by monitoring the amide l width calculated at 3A of the amide height (W3/4H) as a function of the temperature. Right bottom side dependence on temperature for Sulfolobus solfataricus p-glycosidase. (Likhtenshtein et al., 2000). Reproduced with permission.

Auria, S. D., Moracci, M., Febbraio, F., Tanfani, F., Nucci, R., and R., M. (1998) Structure-function studies on p-glycosidase from Sulfolobus solfataricus molecular bases of thermostability, Biochimie 80, 949-957. 

Bismuto, E., Nucci, R., Rossi, M., and Irace, G. (1999) Structural and dynamic aspects of p- glycosidase from mesophilic and thermophilic bacteria by multitryptophanyl emission decay studies, Proteins Struct., Fund., Genet. 35, 163-172. 

The release of glycosidically-bound aroma compounds, such as monoterpenes, C13 norisoprenoids, and aliphatic alcohols, can be achieved by the action of glycosi-dase enzymes. 3-Glycosidase activity has not been much studied in wine LAB. McMahon et al. (1999) detected a low p-glycosidase activity in O. oeni OSU and a... 

Lenman, M., Falk, A., Xue, J. and Rask, L. (1993b) Characterization of a Brassica napus myrosinase pseudogene myrosinases are members of the BGA family of p-glycosidases. Plant Mol. Biol., 21, 463-74. 

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