Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human alpha-L-fucosidase, purified from placenta, was taken up from the culture medium by skin fibroblasts from patients with fucosidosis (alpha-L-fucosidase deficiency). The rate of uptake was low (uptake coefficient = 6 X 10(-4) ml.mg-1.h-1). Intracellular alpha-L-fucosidase activity was directly proportional to enzyme in the medium up to an activity of at least 40 nmoles/min/ml. No evidence for saturation of specific cell-surface receptors was seen. However, uptake was reduced by 75% by 1 mM mannose-6-phosphate and by 50% by 1mM glucose-6-phosphate, suggesting that uptake may be mediated by a receptor recognising a phosphorylated sugar or an analagous compound. Enzyme taken up by the cells was most active in subcellular fractions enriched with lysosomes and had an isozyme pattern, by isoelectric focusing, identical to that of the original enzyme preparation. Fucosidosis fibroblasts were shown to accumulate low molecular-weight, fucose-containing compounds to a level several times greater than control cells. This stored material was eluted from Sephadex G-25 as an asymmetrical peak with an elution volume of approximately twice the void volume of the column. Addition of placental alpha-L-fucosidase to the culture medium of fucosidosis fibroblasts prevented excessive accumulation of fucose-containing material and accelerated the breakdown of material accumulated prior to enzyme uptake.
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PMID:Metabolic correction of fucosidosis fibroblasts by human alpha-L-fucosidase. 76 98

Glycogen and free-glucose content in the ventral, central and dorsal parts, as well as glucose-6-phosphate phosphatase activity in mantle of Mytilus galloprovincialis Lmk. were examined. The glycogen content of mantle did not manifest asymmetrical distribution among the three parts. In the period studied, the typical glycogen content profile variation was found, being maximum in July. The tissue free-glucose content was similar in each part, and the obtained seasonal variation profile was opposite to the glycogen content, reaching the minimum in July. For every part of mantle, free-glucose/glycogen ratio showed similar monthly profiles. In each part the 50% point was found in July. Glucose-6-phosphate phosphatase activity was not found in the mantle tissue.
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PMID:[Zonal variability and seasonal changes of the content of glycogen and glucose in the Mytilus mantle]. 254 90

The dynamic properties of the glucose/glucose-6-phosphate cycle are studied under conditions where the phosphatase and kinase interconverting enzymes are spatially distributed. A semi-artificial membrane made of compacted plant cell walls bearing active phosphatase in its natural state, separates two compartments, one of these compartments containing soluble hexokinase. Depending only upon the two enzyme activity levels and the initial distribution of the substrates, numerous asymmetrical and vectorial behaviours can be observed, such as facilitated glucose 6-phosphate diffusion, active transport of either glucose or glucose 6-phosphate and sequential (alternative) transport between glucose and glucose 6-phosphate. A diffusion-partition reaction coupling can account for these oriented mass transfers. The possibility of such a coupling in this model system is clearly dictated by the global analog of the Curie principle. These results may provide new insight on (a) the still obscure role played by the cell-wall phosphatase activities, particularly their involvement in the transport of exogenous phosphomonoesters, and (b) the actual in vivo operation of substrate and protein cycles in view of the heterogeneity and anisotropy of the cellular milieu.
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PMID:Various vectorial behaviours of a spatially structured substrate cycle. 805 73