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PubMed1990

Effect of acid-base changes on urinary hydrolases in Fabry's disease after renal transplantation.

Fabry's disease, which is characterized by alpha-galactosidase A (AG) deficiency, causes early renal failure. Kidney transplants do not reliably supply the deficient enzyme. To assess both urinary excretion of AG by the transplant and the relationship between urine and serum hydrolase activity, acute and chronic acid-base studies were performed in normal control subjects and in the patient with Fabry's disease who had undergone renal transplantation. For the acute studies, alkalosis was induced by intravenous infusion of sodium bicarbonate and acidosis was induced by ingestion of ammonium chloride. The chronic study involved long-term ingestion of NH4Cl by only the patient with Fabry's disease. The results show that AG is secreted by the renal graft. Urinary hydrolase excretion was increased by acute alkalinization and decreased by acute acidification. Acute, but not chronic, acidification increased the patient's serum AG activity, indicating that long-term acidification is not useful for treating Fabry's disease after transplantation. The large changes in hydrolyase excretion induced by acute and chronic acid-base changes show the difficulty of using lysosomal enzymuria as a diagnostic marker for renal disorders without knowledge of acid-base conditions.

Adult↗

PubMed1988

Further characterization of bleomycin-resistant HeLa cells and analysis of resistance mechanism.

Bleomycin (BLM)-resistant HeLa cells (HeLa-BLMr), which have been subcultured for more than 150 passages during over 2 years in the presence of 1 micrograms/ml of BLM and stably possess a 20-fold-increased BLM-resistance in vitro, were further characterized. The nude mouse tumors produced by HeLa-BLMr were significantly less sensitive (P less than 0.005-0.01) to BLM administration than those produced by HeLa cells, and the cells primarily cultured from nude mouse tumors of HeLa-BLMr and transplanted serially 5 times in the absence of BLM also exhibited a similar degree of BLM resistance to that of HeLa-BLMr cultured in BLM-containing medium. The BLM-resistance mechanism of HeLa-BLMr was partially analyzed. The cells showed about 40% decreased accumulation and 2-3 times reduced retention of [3H]peplomycin, a novel BLM analog, as compared to HeLa cells, but the BLM-hydrolase activity was at almost the same level as that of HeLa cells when determined by HPLC. Furthermore, alkaline sucrose gradient analysis of cellular DNA after BLM treatment revealed that the damaged DNA was more efficiently repaired in HeLa-BLMr than in HeLa cells. These results suggest that decreased drug accumulation and retention, and elevated DNA repair activity are the main mechanism of BLM resistance in HeLa-BLMr.

Animals↗

PubMed2000

Cloning, expression and biochemical characterisation of a unique thermostable pullulan-hydrolysing enzyme from the hyperthermophilic archaeon Thermococcus aggregans.

The gene for a new type of pullulan hydrolase from the hyperthermophilic archaeon Thermococcus aggregans was cloned and expressed in Escherichia coli. The 2181-bp open reading frame encodes a protein of 727 amino acids. A hypothetical membrane linker region was found to be cleaved during processing in E. coli. The recombinant enzyme was purified 70-fold by heat treatment, affinity and anion exchange chromatography. Optimal activity was detected at 95 degrees C at a broad pH range from 3.5 to 8.5 with an optimum at pH 6.5. More than 35% of enzymatic activity was detected even at 120 degrees C. The enzyme was stable at 90 degrees C for several hours and exhibited a half-life of 2.5 h at 100 degrees C. Unlike all pullulan-hydrolysing enzymes described to date, the enzyme is able to attack alpha-1,6- as well as alpha-1,4-glycosidic linkages in pullulan leading to the formation of a mixture of maltotriose, panose, maltose and glucose. The enzyme is also able to degrade starch, amylose and amylopectin forming maltotriose and maltose as main products.

Amino Acid Sequence↗

PubMed1975

[Dosage and cariostatic effect of mutanase in a rat experiment].

In caries tests on rats, mutanase (mu-1,3-glucanglucano-hydrolase) was admixed in different quantities to a cariogenic diet. The animals were fed eight times a day with a feeding machine for 25 days. A highly significant inhibition of fissural caries was achieved by concentrations of over 50 MU per gram of diet. As a simultaneous plaque reduction was not observed, the effect of the enzyme appears to be due to reduced adhesion or colonization capacity of streptococcus mutans strains in the fissures.

Animals↗

PubMedDate not supplied

[Hydrolytic enzymes in biological fluids and skeletal muscle of rats with adjuvant arthritis].

Activities of several hydrolases were studied in blood serum, synovial fluid and musculus femoris of rats with adjuvant arthritis. Alterations in activity of some hydrolases in blood serum were investigated after treatment of animals with nonsteroid antiinflammatory drugs (indometacin, aspirin, bruphene), prednisolone or after the treatment with immunodepressants (imurane, D-penicillamine) and theophylline. Distinct activation of several lysosomal enzymes was observed in rats with arthritis: acidic cathepsins and beta-D-glucuronidase--in all the samples studied; beta-D-galactosidase--in synovial fluid and musculus femoris; hyaluronidase--in synovial fluid and blood serum as well as alpha-D-galactosidase and arylsulfatases (A + B)--in the latter. Activation of these enzymes was accompanied by a decrease in activity of other hydrolases: beta-D-glucosidase, hyaluronidase and alpha-D-galactosidase--in musculus femoris; alpha-D- and beta-D-glucosidases--in blood serum. In treatment of the impaired rats aspirin was the most effective drug, bruphene was less effective. Only theophylline among the drugs studied activated distinctly alpha-D-glucosidase in blood serum. Combination of nonsteroid antiinflammatory drugs (like aspirin and bruphene) with theophylline was apparently the most suitable way for treatment of arthritis under the experimental conditions.

Acid Phosphatase↗

PubMed1982

Studies on the alpha-glucoside hydrolase inhibitor, adiposin. III. alpha Glucoside hydrolase inhibitory activity and antibacterial activity in vitro.

Adiposin-1 and -2 exhibited potent inhibitory activities against alpha-amylase, human salivary alpha-amylase and disaccharidases isolated from porcine small intestine. The effect of adiposin-1 and -2 on hydrolysis of glucoamylase was non-competitive. Adiposin showed antimicrobial activities against some Gram-positive bacteria, Gram-negative bacteria belonging to Enterobacteriaceae, Some anaerobic bacteria and some phytopathogenic fungi, and showed a synergistic effect on the antibacterial activity with some maltooligosaccharides. However, these antibacterial activities were suppressed by addition of various other saccharides.

Amino Sugars↗

PubMed1992

Studies on variations of glycoproteins and lysosomal hydrolases in human uterine cervical carcinoma.

Variations of glycoprotein components such as hexose, hexosamine, and sialic acid and lysosomal glycosidases such as beta-D-glucosidase, beta-D-galactosidase, and N-acetyl-beta-D-glucosaminidase were studied in the tumor tissue from various stages of cervical carcinoma of the uterus. Carbohydrate components of glycoprotein were found to be markedly reduced, and the reduction was very much significant in hexosamine and sialic acid in the advanced stages. Lysosomal glycosidases exhibited a significant increase, and among them N-acetyl-beta-D-glucosaminidase exhibited a prominent increase, in the advanced stages of cervical carcinoma of the uterus.

Carbohydrates↗

PubMed1972

Lysosomes in rat thoracic duct lymphocytes.

10 acid hydrolases known to be lysosomal in other tissues were detected in rat thoracic duct lymphocytes (TDL). Except for cathepsin D, all these enzymes occurred in lower levels in TDL than in rat spleen. Fractionation by means of differential centrifugation revealed two types of distribution patterns. Most of the total cathepsin D activity appeared in a high-speed supernatant (S), whereas the other acid hydrolases associated mainly with a high-speed pellet (P). Further studies by isopycnic centrifugation in a sucrose density gradient showed that all the enzymes, including a small portion of cathepsin D, sedimented around a modal density of 1.18. In contrast, most cathepsin D activity was recovered in a soluble, unsedimentable form. These results suggest the presence of two populations of lysosomes. Because the possibility could be excluded that other cell types contaminated the lymphocyte preparations, it is concluded that both lysosomal populations arise from TDL.

Animals↗

PubMed2000

Multidomain and multifunctional glycosyl hydrolases from the extreme thermophile Caldicellulosiruptor isolate Tok7B.1.

DNA sequencing techniques have revealed widespread molecular diversity of the genomic organization of apparently closely related bacteria (as judged from SSU rDNA sequence similarity). We have previously described the extreme thermophile Caldicellulosiruptor saccharolyticus, which is unusual in possessing multi-catalytic, multidomain arrangements for the majority of its glycosyl hydrolases. We report here the sequencing of three gene clusters of glycosyl hydrolases from Caldicellulosiruptor sp. strain Tok7B.1. These clusters are not closely linked, and each is different in its organization from any described for Cs. saccharolyticus. The catalytic domains of the enzymes belong to glycosyl hydrolase families 5, 9, 10, 43, 44, and 48. The cellulose binding domains (CBDs) of these enzymes from Caldicellulosiruptor sp. Tok7B.1 are types IIIb, IIIc, or VI. A number of individual catalytic and binding domains have been expressed in Escherichia coli, and biochemical data are reported on the purified enzymes for cellulose degradation encoded by engineered derivatives of celB and celE.

Amino Acid Sequence↗

PubMed1979

Determination of lysosomal enzymes in saliva. Confirmation of the diagnosis of metachromatic leukodystrophy and fucosidosis by enzyme analysis.

This paper deals with the measurement of acid hydrolases in uncentrifuged and centrifuged saliva of normal controls and the determination of some of their physical characteristics such as pH optimum, thermal stability, and residual activity after freezing and storage. From this study it appears that beta-D-glucosidase sediments totally, whereas the other enzymes show varying residual activity in the supernatant after centrifugation. In the saliva from 2 patients with metachromatic leukodystrophy and 2 patients with fucosidosis a deficiency of arylsulphatase A and alpha-L-fucosidase, respectively, was found.

Carbohydrate Metabolism, Inborn Errors↗

PubMedDate not supplied

Influence of bioflavonoids on lysosomal acid hydrolases and lysosomal stability.

In rats treated with (+)-catechin or 0-(beta-hydroxyethyl) rutosides, the activity of lysosomal acid hydrolase, namely, beta-glucuronidase, beta-N-acetyl glucosaminidase and cathepsin D in serum, liver and kidney and the stability of liver lysosomes was studied. The activity of these enzymes in bioflavonoids treated tissues and serum decreased significantly. Analysis of liver lysosome-rich fraction revealed an appreciable increase in the total activity and significant decrease in the rate of release of beta-glucuronidase in bioflavonoids treated animals. The results may, therefore, suggest stabilization of lysosomes due to the administration of bioflavonoids.

Acetylglucosaminidase↗

PubMed1985

Effect on lysosomes of invertase endocytosed by rat-liver.

The intracellular localization of invertase endocytosed by rat liver was investigated by analytical centrifugation in sucrose and Percoll gradients of mitochondrial fractions originating from rats killed 15 h after injection. After isopycnic centrifugation in a sucrose gradient, invertase is located in higher density zones than acid hydrolases. The difference between the distribution of invertase and that of acid hydrolases increases with the amount of invertase injected. When the invertase dose is sufficiently high, a change of lysosomal enzyme distribution is clearly visible. It consists in the shift of a proportion of these enzymes to higher density regions where invertase is located. The proportion of hydrolase activity affected by invertase is different for each enzyme measured; it is the least pronounced for acid phosphatase, and most for acid deoxyribonuclease and arylsulfatase. A pretreatment of the rat with Triton WR 1339 considerably decreases the equilibrium density of structures bearing invertase. Nevertheless invertase distribution is quite distinct from that of the bulk of lysosomal enzymes that are recovered in lower density zones of the gradient; on the other hand the invertase injection to rats treated with Triton WR 1339 causes a spreading of the acid hydrolase distribution towards higher density zones. The distribution of acid hydrolases and invertase in a Percoll gradient depends on the sucrose concentration of the solvent. It is shifted towards higher densities when the sucrose concentration increases. The phenomenon is more important for invertase. These results are best explained by supposing that invertase accumulates in a distinct population of lysosomes that can be individualized as a result of the density increase they are subjected to by the invertase they accumulate. It is proposed that these lysosomes mainly originate from non-parenchymal cells of the liver.

Animals↗

PubMedDate not supplied

Studies on the activity of selected lysosomal exoglycosidases in patients with systemic lupus erythematosus.

The activity of selected lysosomal hydrolases ( (beta-galactosidase, beta-N-acetylglucosaminidase, beta-xylosidase, alpha-mannosidase, alpha-fucosidase) was determined in the blood serum of patients with systemic lupus erythematosus (SLE). An increased activity of all the enzymes studied was found as compared to control subjects. Presumable mechanisms of the observed changes are discussed. It is suggested that the studied enzymes may be responsible for the desintegration of the connective tissue ground substance in SLE.

Acetylglucosaminidase↗

PubMed1994

The oligosaccharides of the Fe(III)-Zn(II) purple acid phosphatase of the red kidney bean. Determination of the structure by a combination of matrix-assisted laser desorption/ionization mass spectrometry and selective enzymic degradation.

Purple acid phosphatase of the common bean Phaseolus vulgaris (KBPase), a dimeric 110-kDa glycoprotein related to the mammalian purple acid phosphatases with a two-metal cluster at the active site contains five oligosaccharide side chains/monomer. The N-linked glycan structures were characterized by selective enzymic degradation in combination with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The purified protein was cleaved by cyanogen bromide. One 30-kDa large methionine-free fragment required a further tryptic digest. The peptides were separated by HPLC and the glycosylated species were identified both by their heterogeneous mass spectra and by an immunoassay. None of the glycopeptides proved to have more than one glycosylation site. The composition of the carbohydrate moieties were calculated by comparing the mass spectra of the glycopeptides before and after enzymic deglycosylation. These results were complemented by data from a carbohydrate composition analysis. In four of the five peptides an alpha 1-3 fucose attached to the asparagine-linked N-acetylglucosamine prevented removal of the glycan by peptide N-glycosidase F; peptide N-glycosidase A removed all carbohydrates from the peptides. To reveal the sequence of the carbohydrate moiety including the linkage positions between the different saccharides, one of the glycopeptides was degraded by specific exoglycosidases. The enzymic degradations by these hydrolases were monitored by mass spectrometry of small aliquots taken at intervals during the reaction. The detailed structure of this one glycan in conjunction with the respective mass spectra and the composition analysis were used to infer the structure of the other four glycans. All glycans of the KBPase have a complex-type xylose-containing structure with four of the five having an additional fucose.

Acid Phosphatase↗

PubMed1986

Molecular cloning and characterization of scrB, the structural gene for the Streptococcus mutans phosphoenolpyruvate-dependent sucrose phosphotransferase system sucrose-6-phosphate hydrolase.

A DNA fragment encoding the sucrose-6-phosphate hydrolase component of the Streptococcus mutans phosphoenolpyruvate-dependent sucrose phosphotransferase system has been recovered from a plasmid-based genomic library of strain GS5. The locus, designated scrB, was found to reside within a 2.9-kilobase-pair restriction fragment present on the chimeric molecule pVA1343 (7.3 kilobase pairs). Minicell analysis of pVA1343-directed translation products revealed that the scrB product synthesized in Escherichia coli V1343 was a single peptide of Mr 57,000. This polypeptide was reactive with antiserum prepared against S. mutans intracellular invertase, which has been previously shown to have an Mr of 43,000 to 48,000. The basis of this difference in Mr was not established but may represent a posttranslational proteolytic event which occurred in S. mutans but not in recombinant V1343. Sucrose-6-phosphate hydrolase purified to homogeneity from V1343 exhibited Michaelis constants of 180 mM for sucrose and 0.08 mM for sucrose-6-phosphate. Deletion analysis of pVA1343 facilitated the assignment of a coding region for the hydrolase within the insert, as well as an orientation for the transcription of scrB. scrB-defective strains of S. mutans constructed by additive integration of an insertionally inactivated scrB locus exhibited the sucrose sensitivity characteristic of this mutant class. Similar loci were detected by DNA-DNA hybridization in additional strains of S. mutans and two strains of Streptococcus cricetus, but not in single strain representatives of S. rattus, S. sobrinus, S. sanguis I and II, S. salivarius, or S. mitis.

Animals↗

PubMed1979

Photosensitivity and cutaneous acid hydrolases in porphyria cutanea tarda.

In the present study the participation of lysosomal enzymes in the primary photosensitizing process in the skin of porphyric patients were investigated. Cutaneous photosensitivity reactions were produced in patients with porphyria cutanea tarda by irradiation with near UV light and also to a lesser degree with visible light. The reactions occurred almost exclusively in patients with urinary uroporphyrin excretion exceeding 900 nmol/24 h and preceeded any noticeable increase of lysosomal enzyme activity by several hours. These results indicate that lysosomal enzymes are not primarily involved in the photosensitizing reaction in porphyric patients but that they participate in the cutaneous inflammatory process in porphyric skin at a later stage.

Acid Phosphatase↗

PubMed1983

Inhibition of the release of prostaglandins, leukotrienes and lysosomal acid hydrolases from macrophages by selective inhibitors of lecithin biosynthesis.

The release of the inflammatory mediators, prostaglandins (PGs), leukotrienes (LT) and lysosomal acid hydrolases (LAH), by macrophages is stimulated by endocytic stimuli such as zymosan. This process can be interfered with by specific inhibitors of phosphatidylcholine (PC) biosynthesis. The diphenylsulfone dapsone and three analogs selectively inhibited [14C]choline incorporation into PC but had varied effects on inhibition of mediator release by macrophages. Dapsone inhibited the release of PGs, LT and LAH, whereas the three closely related structural analogs inhibited LAH release only, with little or no effect on PG production.

Animals↗

PubMed1991

Transposon-encoded sucrose metabolism in Lactococcus lactis. Purification of sucrose-6-phosphate hydrolase and genetic linkage to N5-(L-1-carboxyethyl)-L-ornithine synthase in strain K1.

Sucrose-6-phosphate hydrolase from Lactococcus lactis subsp. lactis K1-23 (formerly Streptococcus lactis K1-23) has been purified 600-fold to electrophoretic homogeneity. Purification of the enzyme was achieved by DEAE-Sephacel, phosphocellulose P-11, and gel exclusion (Ultrogel AcA 54) chromatography. The purified enzyme (specific activity 31 units/mg) catalyzed the hydrolysis of both 6-O-phosphoryl-alpha-D-glucopyranosyl-1,2-beta-D-fructofuranoside (sucrose 6-phosphate) and sucrose (Km = 0.1 and 100 mM, respectively). Ultracentrifugal analysis of sucrose-6-phosphate hydrolase indicated an Mr = 52,200. The purified enzyme migrated as a single protein during sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Mr = 52,000). However, four distinct polypeptides were detected by analytical electrofocusing, and all four species hydrolyzed sucrose and sucrose 6-phosphate. The amino acid composition of sucrose-6-phosphate hydrolase, and the sequence of the first 12 amino acids from the NH2 terminus, have been determined. Hybridization studies with oligonucleotide probes show that the genes for sucrose-6-phosphate hydrolase (scrB), Enzyme IIScr of the phosphoenolypyruvate-dependent sucrose:phosphotransferase system (scrA), and N5-(carboxyethyl)ornithine synthase (ceo) are encoded by the same approximately 20-kilobase EcoRI fragment. This fragment is part of a large transposon Tn5306 that also encodes the nisin precursor gene, spaN, and IS904. In L. lactis ATCC 11454, spaN, IS904, scrA, and scrB (but not ceo) are encoded on a related transposon, Tn5307.

Amino Acid Oxidoreductases↗