Glycosylated alkaline phosphatase

The significance of cadherin-like proteins as receptors has been demonstrated by ectopic expression in different cell lines [12, 13] and is further corroborated by the presence of mutated cadherin genes in resistant Hdiothis virescens [14, 15] and Pectinophora gossypidla [16, 17] insect strains. In addition, glycolipids and glycosylated alkaline phosphatase have been implicated in Cry binding [18, 19]. 

Albumin, tetanus toxin, autocrine motility factor, interleukin-2, alkaline phosphatase, glycosyl-phosphatidylinositol (GPI)-GFP, polyoma virus, and echo virus 1 (26). 

Firestone and Heath442 found that the alkaline phosphatase (ortho-phosphoric monoester phosphate hydrolase, EC 3.1.3.1) that is induced in cultured cells by dibutanoy 1-cAMP is not detectable in the presence of inhibitors of glycosylation, although messenger RNA is found in proportions that are comparable to those of noninhibited... 

Alkaline phosphatase, acid phosphatase, 5 -nucleotidase, monoacyl hydrolase, ribonuclease, type 1 phosphodiesterase, adenosine triphosphatase, adenyl cyclase, glycosyl transferase, esterases and disaccharidase have been biochemically or cytochemically demonstrated in the tegument of various cestodes (152, 210, 250, 374, 491, 620, 624-626, 651, 718, 763, 776, 898). Several of these enzymes - phosphatases, 5 -nucleotidase and phosphodiesterase - probably have a digestive and/or absorptive function but the role of the others is uncertain. 

Apart from the desired saccharide, a nucleotide side-product is produced which acts as a natural inhibitor on the respective transferase. To shift the equilibrium to the oligosaccharide product the nucleotide has to be removed in vitro. This can be accomplished by the addition of an alkaline phosphatase to the incubation mixture [34a], or by recycling the glycosyl donor if it is a natural compound [34b]. 

Expression of recombinant aprotinins has been achieved in E. coli K12 as a fusion with parts of the MS-2 polymerase gene [16]. In this case the fusion protein is deposited as inclusion bodies. Functionally active aprotinin can be obtained after solubilization and purification of the fusion protein, CNBr (cyanobromide) cleavage and renaturation of the aprotinin moiety. Low-level periplasmic expression of native, properly folded aprotinin has been shown in E. coli employing the E. coli alkaline phosphatase signal sequence [17]. With respect to expression level and ease of purification, it transpired that secretory expression in the yeast Saccharomyces cerevisiae is by far the most attractive system for the production of this aprotinin variant [18]. In addition, due to the absence of an N-glycosylation site there are no problems with non-human glycosylation of the protein in yeast. 

In diabetic rats orally administered 2 g/kg aqueous extract of parsley leaf daily for 28 days, a reduction in blood glucose, serum alkaline phosphatase activity, sialic acid, uric acid, potassium, and sodium levels, and liver lipid peroxidation and non-enzymatic glycosylation levels was observed, along with an increase in GSH levels (Ozsoy-Sacan et al. 2006). A reduction in blood glucose levels was observed in diabetic rats orally administered 2 g/kg of an aqueous extract of parsley leaf daily for 28 days (Yanardag et al. 2003). 

Wong, YW, Low, MG. Phospholipase resistance of the glycosyl-phosphatidylinositol membrane anchor on human alkaline phosphatase. Clin Chem 1992 38 2517-2525. 

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