P-Galactosides

S-type lectins P-Galactoside-binding animal lectins with roles In cell-cell and cell-matrix interactions... 

Fig. 5. Separation of (1) para- and (2) ortho-aminophenyl tetraacetyl 3-D-galactoside, using a polymer imprinted with o-aminophenyl tetraacetyl p-galactoside. Reprinted with permission from Nilsson KGI, Sakguchi K, Gemeiner P, Mosbach, K (1995) J Chromatogr 707 199. Copyright 1995 Elsevier Science...

Hydrolysis of glycosides can also be achieved by the use of specific enzymes, e.g. P-glucosidase for P-glucosides and P-galactosidase for P-galactosides. 

Table 7.10 Product ratios and relative values ofVmaxfor the hydrolysis of p-galactosides hr (i-palactosidasc at 25°C and pH 7.0-7.5"...

H.R. Kaback, E. Bibi, and P.D. Roepe. 1990. P-Galactoside transport in E. coir. A functional dissection of lac permease Trends Biochem. Sci. 8 309-314. (PubMed)... 

M20. Masamune, H., and Yosizawa, Z., Biochemical studies on carbohydrates. CLXXXVI. Oligosaccharides separated after acetolysis of the group mucopolysaccharide from pig gastric mucus. (Second report.) Acetylglucosamine-4-P-galactoside (acetyllactosamine). Tohoku. Exptl Med. 64, 267-270 (1956). 

A derivative of umbelliferyl-p-galactoside serves as a fluorogenic substrate for E. coli (3-galactosidase in this system and solid-phase reagent strips based on this method have been developed. 

Neda, I, Sakhaii, P, Wassmann, A, Niemeyer, U, Gunther, E, Engel, J, A practical synthesis of benzyl a- and allyl p-D-glucopyranosides regioselectively substituted with (CH2)30H groups stereocon-troUed p-galactosidation by cation ir-interaction. Synthesis, 1625-1632, 1999. 

Cotransport of sugars with H+ is especially common in bacteria but also occurs in eukaryotes. For example, the alga chlorella employs hexose / symporters. 2 xhe most investigated cotransporter is probably the lactose (lac) permease from E. coU which enables E. coli to take up lactose and other P-galactosides from very dilute solutions. 23-436 a... 

The Rf values of two unknown compounds found in plain yogurt were identical to those of 7a-hydroxyriboflavin (Rf values 0.32 and 0.21) and riboflavin-p-galactoside (Rf values 0.14 and 0.10), but not to those of other flavin compounds [flavin adenine dinucleotide or FAD (Rf values 0 and 0), flavine mononucleotide or FMN (Rf values 0 and 0.05), 10-hydroxyethylflavin (Rf values 0.71 and 0.40), riboflavin (Rf values 0.55 and 0.32), and 10-formylmethylflavin (7 f values 0.86 and 0.76)] by TLC on silica gel with chloroform-methanol-ethyl acetate (5 5 2) and 1-butanol-benzyl alcohol-glacial acetic acid (8 4 3) as solvents, respectively. -" ... 

Addition of bromine in methanol gives exclusive trans addition (to 2-deoxy-2-bromomethyl glycosides) in approximately equal amounts, except for tribenzylgalactal, which, as expected from the steric restrictions imposed by 04, gives tribenzyl-2-bromo-2-deoxymethyl p-galactoside and tribenzyl-2-bromo-2-deoxymethyl a-L-talopyranoside in a 2.3 1 ratio. Only in the case of the bromomethoxylation of triacetylglucal was it possible to intercept the oxocarbenium ion with azide ion. The Jencks clock, using a value of 7 x 10 s ... 

The p-galactoside-specific lectins produced by oral actinomyces, such as A. naeslundii and. uiscosus, facilitate initial colonization of epithelial surfaces of the mouth and teeth by mediating the attachment of the bacteria to galactose residues either on the surface of the epithelial cells, or on the surface of other bacteria (for example, S. sanguis) which are adsorbed to the enamel of the teeth [162],... 

Lactose is a reducing disaccharide, glucose-P-galactoside, found principally in milk. Normally, there is no significant absorption of lactose from the intestinal tract, and before utilization the disaccharide must be... 

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