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PubMed1966

Trehalase in conidia of Aspergillus oryzae.

Horikoshi, Koki (The Institute of Physical and Chemical Research, Bunkyo-ku, Tokyo, Japan), and Yonosuke Ikeda. Trehalase in conidia of Aspergillus oryzae. J. Bacteriol. 91:1883-1887. 1966.-Trehalases (soluble trehalase and coat-bound trehalase) were found in the conidia of Aspergillus oryzae, and the total activity of the trehalases increased during the germination process. The soluble trehalase was purified by diethylaminoethyl-cellulose column chromatography; its optimal pH, Michaelis constant, and heat stability were studied. In vitro, the trehalases were competitively inhibited by d-mannitol, which was also contained in the conidia. Since the trehalose content in the conidia decreased at an early stage of germination, it was assumed that trehalase might begin to hydrolyze trehalose after the inhibitory effect of d-mannitol decreased.

Aspergillus↗
PubMed1995

Inhibitors of pig kidney trehalase.

Trehazolin, a new trehalase inhibitor isolated from the culture broth of Micromonospora, was reported to be a highly specific inhibitor for porcine and silk worm trehalases with IC50 values of 5.5 x 10(-9) and 3.7 x 10(-9) M, respectively (O. Ando, H. Satake, K. Itoi, A. Sato, M. Nakajima, S. Takashi, H. Haruyama, Y. Ohkuma, T. Kinoshita, and R. Enokita (1991) J. Antibiot. 44, 1165-1168). We also found that trehazolin is a very powerful and quite specific inhibitor against purified pig kidney trehalase, giving an IC50 value of 1.9 x 10(-8) M. Lineweaver-Burk plots showed that this compound was a competitive inhibitor of the trehalase. However, even at concentrations of 200 micrograms/ml, trehazolin did not inhibit the rat intestinal maltase or sucrase, yeast alpha-glucosidase or almond beta-glucosidase. Validoxylamine A and validamycin A, two other trehalase inhibitors, showed potent competitive inhibition against purified pig kidney trehalase, with IC50 values of 2.4 x 10(-9) and 2.5 x 10(-4) M, respectively. On the other hand, validoxylamine A was almost inactive against rat intestinal sucrase and maltase, with some inhibition being observed at millimolar concentration. A number of other glucosidase inhibitors, such as MDL 25637, castanospermine, and deoxynojirimycin were also tested against the purified trehalase and showed reasonable inhibitory activity.

1-Deoxynojirimycin↗
PubMed1981

Trehalase activity in extracts of Phycomyces blakesleeanus spores following the induction of germination by heat activation.

The heat activation of trehalase in extracts of sporangiospores of Phycomyces blakesleeanus, following the induction of germination by heat activation and the gelatinization of potato starch granules were studied under different conditions in order to discriminate between several phenomena as possible triggers in the activation of trehalase. Short-chain alcohols (from methanol to pentanol) lower the activation temperature of trehalase while long-chain alcohols (from heptanol to nonanol) raise it. Short-chain alcohols also lower the gelatinization temperature of potato starch granules, while long-chain alcohols, hexanol and heptanol have hardly any influence on the gelatinization temperature. Octanol raises the gelatinization temperature. More polar phenols lower the activation temperature of trehalase, while more apolar phenols will raise it. The gelatinization temperature of starch granules is more lowered by the polar polyphenols than by the more apolar phenols. The effect of high pressure on starch gelatinization was investigated in order to compare data from such a model system with the data on trehalase activation. The gelatinization temperature of starch granules is shifted upwards with about 3-5K/1000 atm (1.013 X 10(5) kPa). Pressures higher than 1500 atm do not further increase the gelatinization temperature. However, no reversal of the effect, as occurs with protein conformational changes, is seen with pressure up to 2500 atm. Also for trehalase activation we find a continuous upward shift of the activation temperature with about 5-9K/1000 atm. These data are in agreement with a thermal transition in a polysaccharide matrix, being the trigger in the heat activation of trehalase.

Ethanol↗
PubMed1985

Control of yeast neutral trehalase by distinct polyphosphates and ribonucleic acid.

The activity of yeast trehalase when assayed at pH 7 in a crude extract was found to increase 2- to 3-fold upon incubation with 0.1% (v/v) polyethyleneimine or other polycations such as polylysine (0.075-mMol) and calf thymus histones (0.08 mMol). Incubation with 3 mM-Mn2+ and 5 mM-Ca2+ also led to 3- and 1.6-fold increases in trehalase activity, respectively. The activities of 11 other enzymes assayed in the crude yeast extract did not increase after addition of polyethylene imine. At concentrations of polyethyleneimine that maximally stimulated trehalase activity, 97% of the total RNA present in the crude extract, 40% of total protein, and 60% of the polyphosphate (assayed as inorganic phosphate liberated during 7 min incubation at 95 degrees C and pH O) were found to be precipitated. A similar finding was made with trehalase-stimulating concentrations of Mn2+. Activation of trehalase by polyethylene imine rendered this enzyme susceptible to inhibition by a preparation of total yeast RNA, inorganic polyphosphates, and related polyanions. We present further evidence that the removal of a distinct RNA and/or polyphosphate is the basic principle of polyethyleneimine-induced activation of trehalase. A more pronounced stimulation of trehalase activity (4-fold) could be obtained by enzymatic phosphorylation with ATP in the presence of cyclic AMP and Mg2+ as described by van Solingen and van der Plaat (1975) [9].(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1993

Fetal intestinal and renal origins of trehalase activity in human amniotic fluid.

Intestinal and renal trehalase isozymes have been distinguished in normal human amniotic fluid on the basis of their membrane-bound character and isoelectric point (pI). The intestinal trehalase was mostly membrane bound in amniotic fluid and had a pI around 4.60. In contrast, the renal form of trehalase was soluble and had a pI around 4.37. These pI values were consistent with those found in extracts of fetal intestinal (pI 4.60) and renal (pI 4.24) tissues. The determination of trehalase isozyme composition of amniotic fluid from pathological pregnancies with anal imperforation and polycystic kidney disease confirmed our findings on the origin of amniotic fluid trehalase. In the sample from a fetus with anal imperforation, low or absent intestinal trehalase isozyme was observed whereas a higher than normal level of renal trehalase activity was found in a fetus with polycystic kidney disease.

Amniotic Fluid↗
PubMed1994

Differential changes in the activity of cytosolic and vacuolar trehalases along the growth cycle of Saccharomyces cerevisiae.

Saccharomyces cerevisiae cells contain two intracellular and soluble trehalases with distinct subcellular location (cytosol and vacuoles, respectively). Both enzymes showed an opposite pattern of activity along the growth cycle. Activity of the cytosolic trehalase was high in cells growing exponentially on fermentable sugars (glucose, mannose or galactose) and sharply decayed as the cultures enter stationary phase coinciding with the beginning of trehalose biosynthesis. By contrast, vacuolar trehalase was only detectable in glucose-grown resting cells or in cultures growing on respiratory substrates (glycerol or ethanol). This enzyme was partially derepressed in the mutant hex2, which is deficient in glucose repression. Addition of fresh YPD medium to stationary-phase cultures induced the sudden reactivation of cytosolic trehalase with the concomitant slower inactivation of vacuolar trehalase. However, addition of glucose or various nitrogen sources alone had only a minor effect on both activities. The presence of cycloheximide had no effect on cytosolic trehalase, whereas completely blocked the appearance of vacuolar trehalase suggesting the requirement of protein synthesis 'de novo'.

Cycloheximide↗
PubMed1995

Trehazolin, a slow, tight-binding inhibitor of silkworm trehalase.

Mechanisms of enzyme inhibition by trehazolin, a new inhibitor of trehalase (Ando et al. (1991) J. Antibiot. 44, 1165), were investigated using purified soluble silkworm trehalase and other glycosidases. Trehazolin inhibited trehalase with an IC50 value of 27 nM, whereas some other exo-alpha-glucosidases were inhibited only weakly, with IC50 values ranging from 7 to 370 microM. Other glycosidases tested were not inhibited by 500 microM trehazolin. The inhibition of trehalase by trehazolin was competitive with respect to trehalose. A notable feature of the inhibition was a slow progression of the association and dissociation of the enzyme-inhibitor complex. Preincubation of the enzyme and the inhibitor at 37 degrees C potentiated the inhibition by 10-times in a time-dependent manner up to 6 h. Dialysis of the inactivated enzyme recovered the enzymatic activity very slowly, and the rate constant for the dissociation at 37 degrees C was (7.3).10(-2) h-1. Trehalamine, a deglucosylated form of trehazolin, inhibited both silkworm trehalase and exo-alpha-glucosidases only weakly. The inhibition of trehalase by trehalamine was reversible. Rat isomaltase inhibition by trehazolin and sucrase inhibition by trehalamine were also reversible. Taken together, trehazolin is a specific slow, tight-binding inhibitor of trehalase, and the glucose moiety of the inhibitor is essential to the tight binding.

Animals↗
PubMed1985

Neurospora trehalase and its structural gene.

We have isolated Neurospora trehalaseless mutants and mapped the trehalase structural gene to linkage group I. The structural gene mutations not only affect thermostability and other characteristics of the enzyme but also affect the production of an inhibitor of the wild-type trehalase. The inhibitor appears to be the mutant trehalase. We suggest that the mutant subunits act as inhibitors by entering into the multimeric forms of the enzyme and altering the ability of the normal wild-type subunits to catalyze the cleavage of trehalose.--Wild type trehalase has been purified to near homogeneity, and its characteristics have been studied. It was purified as a tetramer, with each subunit having a molecular weight of 88,000.--We have studied the regulation of trehalase and found the production of trehalase to be glucose repressible. Cells begin to produce trehalase 60 min after being transferred to glucose-free medium.

Genes↗
PubMed1997

Protein kinase Sck1 is involved in trehalase activation by glucose and nitrogen source in the fission yeast Schizosaccharomyces pombe.

Trehalase activity is markedly enhanced upon addition of glucose and a nitrogen source to cells of the fission yeast Schizosaccharomyces pombe. This increase corresponds to a post-translational activation of the enzyme, which is controlled by cAMP-dependent and cAMP-independent pathways. Recent work has shown that overexpression of SCK1 in Schiz. pombe is able to suppress mutations that result in reduced Pka1 (cAMP-dependent protein kinase A activity, suggesting that Sck1 (suppressor of loss of cAMP-dependent protein kinase) might be a functional analogue of Pka1 in the fission yeast. Here, an analysis of the possible role of Sck1 in the activation of trehalase triggered by glucose and a nitrogen source is reported in cells that were deficient in either Pka1, Sck1 or both protein kinases. The results showed that, except in repressed cells, Sck1 probably mediates a cAMP-independent activation of trehalase following the signal(s) triggered by glucose and the nitrogen source. The absence of functional Sck1 in depressed cells renders trehalase insensitive to activation by glucose and the nitrogen source even in the presence of Pka1, indicating that the Sck1-dependent, cAMP-independent pathway is the main signalling pathway controlling trehalase activation under derepression conditions. It is proposed that, during the activation of trehalase induced by glucose or a nitrogen source, the cAMP-Pka1 activation pathway previously characterized is to some extent parallel to this newly described one which includes Sck1 as phosphorylating enzyme. Neither of these two pathways, however, plays a key role in the heat-induced increase in trehalase activity.

Enzyme Activation↗
PubMed1996

Two subsites on the active center of pig kidney trehalase.

A kinetic analysis of the active site of pig kidney trehalase was made by examining two types of inhibitors that are monosaccharide analogs and cause a competitive inhibition of the trehalase. Trehalase hydrolyzes trehalose (alpha-D-glycopyranosyl alpha-D-glucopyranoside) to give an equimolar mixture of alpha-D-glucose and, by inversion of configuration, beta-D-glucose. 1,4-Dideoxyl-1,4-imino-D-arabinitol is considered to be a transition state (glucosyl cation) analog, while methyl beta-D-glucoside, 1,5-dideoxy-1,5-imino-D-glucitol (1-deoxynojirimycin), fagomine, and 1-epivalidamine are considered to be analogs of the beta-D-glucose that is derived by hydrolysis of trehalose. These glucosyl cation inhibitor and beta-D-glucose analog inhibitors competed with each other at the same site on the active center of pig kidney trehalase and were therefore put together in one group (group A). Methyl alpha-D-mannoside and 1-deoxymannojirimycin were also competitive inhibitors of trehalase and competed with each other for the same site. However, an inhibitor in group A did not compete with the methyl alpha-D-mannoside or 1,5-dideoxy-1,5-imino-D-mannitol (1-deoxymannojirimycin). Thus these latter two inhibitors were placed in group B. These results support the hypothesis that the active center of trehalase may comprise two subsites, one for catalysis and one for recognition, that act separately on each of the glucose of the trehalose. The catalysis site requires the correct D-glucose configuration at carbons 2, 3, 4, and 5 or a good superimposition onto the glucosyl cation intermediate. The C2 equatorial OH group of a glucopyranosyl residue appears to be important for binding at the catalytic site since 1-deoxynojirimycin is more tightly bound by two orders of magnitude over its 2-deoxy derivative, fagomine. The beta-D-glucose and glucosyl cation analogs best fit this site. The recognition site is compatible with D-glucose and its analogs bearing the alpha configuration at the anomeric position. alpha-D-Mannose analogs are much more tightly bound than the corresponding D-gluco compound at this site. The extremely high affinity (Ki = 0.52 nM) of validoxylamine A, a mimic of the substrate in the transition state, derives from the synergistic interactions of two cyclitol units with two subsites. The value obtained by multiplying the Ki (1.2 microM) for 1-epivalidamine times that for 1-deoxymannojirimycin (Ki = 0.39 mM) is very close to that for validoxylamine A. The results described here may be applicable to other trehalase molecules.

Animals↗
PubMed1983

Regulation of yeast trehalase by a monocyclic, cyclic AMP-dependent phosphorylation-dephosphorylation cascade system.

Mutation at the GLC1 locus in Saccharomyces cerevisiae resulted in simultaneous deficiencies in glycogen and trehalose accumulation. Extracts of yeast cells containing the glc1 mutation exhibited an abnormally high trehalase activity. This elevated activity was associated with a defective cyclic AMP (cAMP)-dependent monocyclic cascade which, in normal cells, regulates trehalase activity by means of protein phosphorylation and dephosphorylation. Trehalase in extracts of normal cells was largely in a cryptic form which could be activated in vitro by ATP . Mg in the presence of cAMP. Normal extracts also exhibited a correlated cAMP-dependent protein kinase which catalyzed incorporation of label from [gamma-32P]ATP into protamine. In contrast, cAMP had little or no additional activating effect on trehalase or on protamine phosphorylation in extracts of glc1 cells. Similar, unregulated activation of cryptic trehalase was also found in glycogen-deficient strains bearing a second, independently isolated mutant allele, glc1-2. Since trehalase activity was not directly affected by cAMP, the results indicate that the glc1 mutation results in an abnormally active protein kinase which has lost its normal dependence on cAMP. Trehalase in extracts of either normal or mutant cells underwent conversion to a cryptic form in an Mg2+-dependent, fluoride-sensitive reaction. Rates of this reversible reduction of activity were similar in extracts of mutant and normal cells. This same, unregulated protein kinase would act on glycogen synthase, maintaining it in the phosphorylated low-activity D-form. The glc1 mutants provide a novel model system for investigating the in vivo metabolic functions of a specific, cAMP-dependent protein kinase.

Adenosine Triphosphate↗
PubMed1993

Urinary trehalase activity in chronic glomerulonephritis.

To determine the diagnostic role of urinary trehalase in chronic glomerular disease, urinary trehalase activity and other urinary markers such as N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), alkaline phosphatase (ALP), gamma-glutamyltranspeptidase (gamma-GTP), lactate dehydrogenase (LDH), lysozyme and beta 2-microglobulin (BMG) were measured in patients with chronic glomerulonephritis, nephrotic syndrome and chronic renal failure. Urinary trehalase activity was significantly increased in chronic glomerular disease, especially nephrotic syndrome, as compared with that in the healthy subjects. The highest incidence of elevated excretion was observed for trehalase with 52% in chronic glomerular disease, followed by NAG. Urinary trehalase activities in the patients were significantly correlated with the urinary levels of protein, NAG and AAP and total score of tubular damage, but not correlated with urinary levels of BMG or lysozyme. In patients with chronic glomerulonephritis and nephrotic syndrome, there was no significant difference in urinary trehalase activities between with and without hematuria. These results indicate that in some patients with chronic glomerular disease, there is tubular involvement as substantiated by elevation of the other urinary enzymes and BMG. Urinary trehalase is elevated more often in these types of disease than other markers of tubular damage.

Acetylglucosaminidase↗
PubMed2001

[Urinary trehalase activity as an indicator of renal dysfunction in lead smelters].

Epidemiological and experimental studies have demonstrated that lead and cadmium are responsible for renal dysfunction. Urinary trehalase is known as a good marker of proximal tubular renal brush border destruction in the population environmentally exposed to cadmium. The aim of this study was to determine the impact of occupational exposure to lead on the renal function and urinary trehalase activity. The study was carried out in 68 workers, aged 46 +/- 6 years, employed in a copper foundry. Blood lead, cadmium, copper and manganese concentrations were measured by atomic absorption spectrophotometry. Urinary trehalase activity was determined by the method of Nakano and Itoh. Trehalase activity was increased in copper smelters as compared to controls. There also was a positive linear correlation between blood lead level and urinary trehalase activity (r = 0.44; p < 0.05). Negative correlations between blood lead and copper concentrations (r = -0.30; p < 0.05) and between serum copper and trehalase level (r = 0.68; p < 0.001) were found. The results show that urinary trehalase activity could be a good indicator of the renal brush border dysfunction in copper smelters. This marker could be useful in the early diagnosis of nephrotoxic effect of lead.

Cadmium↗
PubMed1995

Isolation and characterization of a novel yeast gene, ATH1, that is required for vacuolar acid trehalase activity.

We have isolated a plasmid containing a gene, ATH1, that results in eight- to ten-fold higher acid trehalase activity in yeast cells when present in high copy. The screening procedure was based on overproduction-induced mislocalization of acid trehalase activity; overproduction of vacuolar enzymes that transit through the secretory pathway leads to secretion to the cell surface. A DNA fragment that confers cell surface expression of acid trehalase activity was cloned and sequenced. The deduced amino acid sequence displayed no homology to known proteins, indicating that we have identified a novel gene. A deletion in the genomic copy of the ATH1 gene eliminates vacuolar acid trehalase activity. These results suggest that ATH1 may be the structural gene encoding vacuolar acid trehalase or that the gene product may be essential regulatory component involved in control of trehalase activity.

Amino Acid Sequence↗
PubMed1981

Induction of trehalase activity on a nitrogen-free medium: a sporulation-specific event in the fission yeast, Schizosaccharomyces pombe.

Kinetic experiments with synchronously sporulating cultures of a homothallic h90 strain of Schizosaccharomyces pombe showed that trehalase activity abruptly increased in the late sporulation process, coinciding with the appearance of visible spores. Trehalase activity was absent in vegetative cells. A set of strains different in genetic constitution at the mating type loci was tested for induction of trehalase on nitrogen-free sporulation medium. The appearance of trehalase activity on the sporulation medium was observed only in sporulating cultures; cultures of homothallic strains (h 90) and diploid strains heterozygous for mating type (h +/h-), and mixed cultures of heterothallic h+ and h- strains. Trehalase activity was not induced in nonsporogenic strains: heterothallic haploid strains (h+ and h-), diploid strains homozygous for mating type (h+/h+ and h-/h-) and the homothallic strain harboring the mutation in the mat2 gene, which was unable to undergo the first meiotic division. Trehalose accumulation on the sporulation medium was observed solely in the sporulating cultures. These results led us to conclude that the induction of trehalase activity as well as the accumulation of trehalose in the medium lacking nitrogen sources was a sporulation-specific event under the control of the mating type genes.

Ascomycota↗
PubMed1988

Urinary trehalase activity as an indicator of kidney injury due to environmental cadmium exposure.

One hundred and seventy-eight subjects, patients with Itai-itai disease and their family members, aged 12-87 years living in a cadmium (Cd)-polluted area in the Jinzu River basin (Cd-exposed group) and 176 controls (control group) were examined. In the Cd-exposed group urinary trehalase increased with increasing age, urinary beta 2-microglobulin (beta 2-m) and retinol-binding protein. Although urinary cadmium was higher in the Cd-exposed group, no particular correlation was found between urinary trehalase and urinary cadmium. Seventeen men and 11 women showed raised urinary trehalase activities despite normal values of urinary beta 2-m (less than 300 micrograms/g.creatinine), suggesting that urinary trehalase increases earlier than urinary beta 2-m. In 19 patients with Itai-itai disease included in the Cd-exposed group, urinary trehalase decreased with decreasing reciprocal of serum creatinine, suggesting that urinary trehalase decreases in the most advanced cases of chronic cadmium nephropathy due to reduced tubular cell mass.

Adolescent↗
PubMed1989

Plasma trehalase activity and diabetes mellitus.

Trehalase is an enzyme which hydrolyzes the disaccharide trehalose, yielding glucose. It is widespread in nature and found in various human tissues as well as in human plasma. The synthesis and degradation of its substrate trehalose have been considered as being implicated in carbohydrate transport mechanisms. Trehalase activity has been examined in both normal subjects and diabetic patients. In the normal subjects, the frequency histogram of the enzyme activity is bimodal, indicating the existence of genetic polymorphism. The proposed model of a single autosomal locus with two alleles has been verified, with 27% of the population tested belonging to the "low-activity" phenotype and 73% being of the "high-activity" phenotype. Males have higher mean plasma trehalase activity than females. Apparently, the reverse appears to be the case in the diabetic subjects. The mean value for all nondiabetics and that of diabetics were computed and the difference was found to be statistically significant (F = 7.02, N1 = 3, N2 = 56, P less than 0.01). An experiment showed that neither the abnormally high concentration of glucose in diabetics nor any other constituent of the diabetic plasma caused an increase in plasma trehalase activity (t = 0.0724, P greater than 0.10). A Woolf and Haldane test to determine association of diabetes mellitus and plasma trehalase phenotype indicated a highly significant association with the high-activity phenotype (chi 2 = 18.5350, P less than 0.01). Thus the inference is that people with high plasma trehalase activity are more prone to develop diabetes mellitus than people with low enzyme activity.

Adult↗
PubMed2006

A highly thermostable trehalase from the thermophilic bacterium Rhodothermus marinus.

Trehalases play a central role in the metabolism of trehalose and can be found in a wide variety of organisms. A periplasmic trehalase (alpha,alpha-trehalose glucohydrolase, EC 3.2.1.28) from the thermophilic bacterium Rhodothermus marinus was purified and the respective encoding gene was identified, cloned and overexpressed in Escherichia coli. The recombinant trehalase is a monomeric protein with a molecular mass of 59 kDa. Maximum activity was observed at 88 degrees C and pH 6.5. The recombinant trehalase exhibited a K(m) of 0.16 mM and a V(max) of 81 micromol of trehalose (min)(-1) (mg of protein)(-1) at the optimal temperature for growth of R. marinus (65 degrees C) and pH 6.5. The enzyme was highly specific for trehalose and was inhibited by glucose with a K(i) of 7 mM. This is the most thermostable trehalase ever characterized. Moreover, this is the first report on the identification and characterization of a trehalase from a thermophilic bacterium.

Bacterial Proteins↗