Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effect of different concentration of non-ionic detergents (Triton X-100, Triton X-305, BRIJ-35 and Triton WR-1339) on total and non-sedimentable activity of 8 rat liver lysosome enzymes (acid phosphatase, acid DNase, acid RNase, arylsulphatases A and B, beta-glucuronidase, beta-galactosidase, beta-glucosidase and beta-acetylglucosaminidase) was studied. Only Triton X-100 at the concentration of 0.1% (and higher) was found to release completely lysosome enzymes. Low concentrations of Triton X-100 (0.025-0.05%) were used to characterize the strength of enzyme binding: the level of releasing acid DNase, beta-galactosidase, beta-glucuronidase and acid phsophatase being considerably higher than that of other lysosome enzymes studied. On the basis of the data obtained a method is worked out, which is suitable for series studies of the stability of lysosome membranes under different physiological and pathological conditions. The essence of the method is the treatment of membrane particles with increasing concentrations of Triton X-100 (0.025; 0.05 AND 0.1%) AND THE SUCCESSIVE ESTIMATION OF NON-Sedimentable activity of marker enzymes. The method detected troubles in the stability of rat liver lysosome membranes under starvation, protein deficiency and aging.
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PMID:[Determination of lysosome membrane stability]. 120 72

Various non-ionic surfactants affect the SOS-inducing potency (SOSIP) of the model genotoxin, 4-nitroquinoline-1-oxide, in Escherichia coli PQ37 to varying degrees, as measured by an automated version of the SOS chromotest. While there is little effect on the SOSIP value and other test parameters from Tween 20 and 80 and, with some reservation, Triton X305 and Tyloxapol, over the critical micelle concentration range, the SOSIP value increases in the presence of comparable concentrations of Triton X15, 45 and 100. A possible dependence of the tester strain's beta-galactosidase production and its growth inhibition on the HLB of the non-ionic surfactants added is discussed.
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PMID:The effect of non-ionic surfactants on the SOS-inducing potency of 4-nitroquinoline-1-oxide in Escherichia coli PQ37. 212 82

The effect of in vivo loading of the lysosomotropic agent 125I-Triton WR-1339 on the release of lysosomal enzymes in isolated perfused rat liver has been studied in the presence and absence of the microfilament poison cytochalasin B, as has the release of the 125I-Triton WR-1339 itself. Perfused isolated rat livers released all the enzymes studied (arylsulphatase, beta-galactosidase and lactate dehydrogenase) and, when preloaded, 125I-Triton WR-1339 was also released into the perfusate. The magnitude of the net release (after 5 hr perfusion) was in the order beta-galactosidase = 125I-Triton WR-1339 greater than lactate dehydrogenase greater than arylsulphatase. Preloading of the lysosomes with the detergent appeared to bring about an increase in the release of all the enzymes studied (3.5 X for beta-galactosidase, 2.6 X for arylsulphatase and 1.7 X for lactate dehydrogenase). The addition of the microfilament poison cytochalasin B into the perfusate of non-loaded livers significantly increased the release of the lysosomal enzymes but not that of lactate dehydrogenase. However in the 125I-Triton WR-1339- loaded livers cytochalasin B had no effect on the release of lysosomal enzymes or detergent, but reduced the loss of lactate dehydrogenase by about 50%. This failure of cytochalasin B to potentiate the exocytosis of lysosomal contents in 125I-Triton WR-1339-loaded livers is similar to the effect found previously with 125I-PVP-loaded livers and may be related to the already enhanced loss of lysosomal enzymes apparently caused by the loading.
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PMID:The release of intralysosomally-stored 125I-Triton WR-1339 and lysosomal enzymes from the isolated perfused rat liver in the presence and absence of cytochalasin B. 308 35

Unlike lysosomal soluble proteins, few lysosomal membrane proteins have been identified. Rat liver lysosomes were purified by centrifugation on a Nycodenz density gradient. The most hydrophobic proteins were extracted from the lysosome membrane preparation and were identified by MS. We focused our attention on a protein of approx. 40 kDa, p40, which contains seven to ten putative transmembrane domains and four lysosomal consensus sorting motifs in its sequence. Knowing that preparations of lysosomes obtained by centrifugation always contain contaminant membranes, we combined biochemical and morphological methods to analyse the subcellular localization of p40. The results of subcellular fractionation of mouse liver homogenates validate the lysosomal residence of p40. In particular, a density shift of lysosomes induced by Triton WR-1339 similarly affected the distributions of p40 and beta-galactosidase, a lysosomal marker protein. We confirmed by fluorescence microscopy on eukaryotic cells transfected with p40 or p40-GFP (green fluorescent protein) constructs that p40 is localized in lysosomes. A first molecular characterization of p40 in transfected Cos-7 cells revealed that it is an unglycosylated protein tightly associated with membranes. Taken together, our results strongly support the hypothesis that p40 is an authentic lysosomal membrane protein.
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PMID:Intracellular localization of p40, a protein identified in a preparation of lysosomal membranes. 1636 39

It has been suggested that intracellular Hyal-1 (hyaluronidase-1), which is considered a lysosomal enzyme, originates via endocytosis of the serum enzyme. To test this proposal we have investigated the uptake and intracellular distribution of rhHyal-1 (recombinant human Hyal-1) by mouse liver, making use of centrifugation methods. Experiments were performed on wild-type mice injected with 125I-labelled rhHyal-1 and on Hyal-1-/- mice injected with the unlabelled enzyme, which were killed at various times after injection. Activity of the unlabelled enzyme was determined by zymography. Intracellular distribution of Hyal-1 was investigated by differential and isopycnic centrifugation. The results of the study indicated that rhHyal-1 is endocytosed by the liver, mainly by sinusoidal cells, and follows the intracellular pathway described for many endocytosed proteins that are eventually located in lysosomes. However, Hyal-1 endocytosis has some particular features. First, endocytosed rhHyal-1 is quickly degraded. Secondly, its distribution, as analysed by differential centrifugation, differs from the distribution of beta-galactosidase, taken as the reference lysosomal enzyme. Further analysis by isopycnic centrifugation in a sucrose gradient shows endocytosed rhHyal-1 behaves like beta-galactosidase shortly after injection. However the Hyal-1 distribution is markedly less affected than beta-galactosidase, following a prior injection of Triton WR-1339, which is a specific density perturbant of lysosomes. The behaviour in centrifugation of endogenous liver Hyal-1, identified by hyaluronan zymography, exhibits some similarity with the behaviour of the endocytosed enzyme, suggesting that it could originate from endocytosis of the serum enzyme. Overall, these results can be explained by supposing that active endocytosed Hyal-1 is mainly present in early lysosomes. Although its degradation half-time is short, Hyal-1 could exert its activity due to a constant supply of active molecules from the blood.
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PMID:Endocytosis of hyaluronidase-1 by the liver. 2057 8