scholarly journals Comparison of the activities of a multiple inositol polyphosphate phosphatase obtained from several sources: a search for heterogeneity in this enzyme

1995 ◽  
Vol 305 (2) ◽  
pp. 491-498 ◽  
Author(s):  
A Craxton ◽  
N Ali ◽  
S B Shears

A multiple inositol polyphosphate phosphatase (formerly known as inositol 1,3,4,5-tetrakisphosphate 3-phosphatase) was purified approx. 22,000-fold from rat liver. The final preparation migrated on SDS/PAGE as a doublet with a mean apparent molecular mass of 47 kDa. Upon size-exclusion chromatography, the enzyme was eluted with an apparent molecular mass of 36 kDa. This enzyme was approximately evenly distributed between the ‘rough’ and ‘smooth’ subfractions of endoplasmic reticulum. There was a 20-fold range of specific activities of this phosphatase in CHAPS-solubilized particulate fractions prepared from the following rat tissues: liver, heart, kidney, testis and brain. However, each of these extracts contained different amounts of endogenous inhibitors of enzyme activity. After removal of these inhibitors by MonoQ anion-exchange chromatography, there was only a 2.5-fold range of specific activities; kidney contained the most and brain contained the least. We prepared and characterized polyclonal antiserum to the hepatic phosphatase, which immunoprecipitated 85-100% of both particulate and soluble phosphatase activities. The antiserum also immunoprecipitated, with equivalent efficacy, CHAPS-solubilized phosphatase activities from heart, kidney, testis, brain and erythrocytes (all prepared from rat). Our data strengthen the case that the function of the mammalian phosphatase is unrelated to the metabolism of Ca(2+)-mobilizing cellular signals. The CHAPS-solubilized phosphatase from turkey erythrocytes was not immunoprecipitated by the polyclonal antiserum, and is therefore an isoform that is structurally distinct, and possibly functionally unique.

2001 ◽  
Vol 67 (7) ◽  
pp. 3319-3321 ◽  
Author(s):  
Tatsuji Sakamoto ◽  
Jean-Fran�ois Thibault

ABSTRACT An exo-arabinanase, designated Abnx, was purified from a culture filtrate of Penicillium chrysogenum 31B by ammonium sulfate precipitation, anion-exchange chromatography, and hydrophobic chromatography. Abnx had an apparent molecular mass of 47 kDa. The enzyme released only arabinobiose from the nonreducing terminus of α-1,5-l-arabinan and showed no activity towardsp-nitrophenyl-α-l-arabinofuranoside and α-1,5-l-arabinofuranobiose. Abnx is the first enzyme with this mode of action.


Author(s):  
Ken-ji Yokoi ◽  
Sosyu Tsutsui ◽  
Gen-ya Arakawa ◽  
Masakazu Takaba ◽  
Koichi Fujii ◽  
...  

Abstract Information about the inulosucrase of non-lactic acid bacteria is scarce. We found a gene encoding inulosucrase (inuBK) in the genome of the gram-positive bacterium Alkalihalobacillus krulwichiae JCM 11691. The inuBK open reading frame encoded a protein comprising 456 amino acids. We expressed His-tagged InuBK in culture medium using a Brevibacillus system. The optimal pH and temperature of purified InuBK were 7.0–9.0 and 50 °C–55 °C, respectively. The findings of high-performance anion-exchange chromatography, nuclear magnetic resonance spectroscopy, and high-performance size-exclusion chromatography with multi-angle laser light scattering showed that the polysaccharide produced by InuBK was an inulin with a molecular weight of 3,806, a polydispersity index (PI) of 1.047, and fructosyl chain lengths with 3–27 degrees of polymerization. The size of InuBK was smaller than commercial inulins, and the PI of the inulin that it produced was lower.


1997 ◽  
Vol 153 (3) ◽  
pp. 411-421 ◽  
Author(s):  
W Klootwijk ◽  
R D H de Boer ◽  
E Sleddens-Linkels ◽  
S M Cockle ◽  
W W de Herder ◽  
...  

Abstract TRH-like immunoreactivity (TRH-LI) was estimated in methanolic extracts of rat tissues and blood by RIA using antiserum 4319, which binds most peptides with the structure pGlu-X-ProNH2, or antiserum 8880, which is specific for TRH (pGlu-His-ProNH2). TRH-LI (determined with antiserum 4319) and TRH (determined with antiserum 8880) contents were 8 and 8 ng/g in brain, 216 and 222 ng/g in hypothalamus, 6·5 and 6 ng/g in pancreas, 163 and 116 ng/g in male pituitary, 105 and 77 ng/g in female pituitary, 1 and 0·1 ng/g in salivary gland, 61 and 42 ng/g in thyroid, 12 and 3 ng/g in adrenal, 3 and 0·3 ng/g in prostate, and 11 and 0·8 ng/g in ovary respectively. Blood TRH-LI (antiserum 4319) and TRH (antiserum 8880) levels were 31 and 18 pg/ml in male rats, and 23 and 10 pg/ml in female rats respectively. Unextracted serum obtained from blood kept for at least 1 h at room temperature no longer contained authentic TRH but still contained TRH-LI (males 20·3 ± 3·1, females 15·9 ± 3·0 pg/ml; means ± s.e.m.). Isocratic reverse-phase HPLC showed that TRH-LI in serum is largely pGlu-Glu-ProNH2 (<EEP-NH2), a peptide previously found in prostate and anterior pituitary. In urine, TRH-LI (antiserum 4319) and TRH (antiserum 8880) levels were 3·21 ± 0·35 and 0·32 ± 0·04 ng/ml in male rats and 3·75 ± 0·22 and 0·37 ± 0·04 ng/ml in female rats respectively (means ± s.e.m.). Anion-exchange chromatography on QAE-Sephadex showed that urine of normally fed rats contains both basic/neutral TRH-LI (b/nTRH-LI) and acidic TRH-LI (aTRH-LI) in a ratio of ≈ 40:60, and further analysis by HPLC indicated that aTRH-LI represents <EEP-NH2. Analysis of food extracts and urine from fasted rats demonstrated that b/nTRH-LI is derived from food particles spilled by the rats during urine collection, while aTRH-LI is endogenously produced. While urinary aTRH-LI levels were higher in female than in male rats (2·99 ± 0·41 vs 2·04 ± 0·20 ng/ml), the daily urinary excretion was similar in both sexes (females 15·6 ± 1·4, males 19·5 ± 2·0 ng/day). Intravenously injected <EEP-NH2 disappeared from serum with a half-life of ≈ 1 h, and was recovered unchanged and quantitatively in urine. In contrast, when <EEP-NH2 was administered with food, only ≈ 0·5% was recovered in urine. The urinary clearance rate of serum TRH-LI amounted to 0·52 ± 0·10 ml/min in males and 0·34 ± 0·05 ml/min in females. In view of the presence of <EEP-NH2 in the anterior pituitary gland, and the regulation of its content in parallel with gonadotrophins, we examined the possibility that serum <EEP-NH2 is of pituitary origin and correlates with gonadotrophin secretion. However, treatments that alter pituitary <EEP-NH2 content and gonadotrophin release had no effect on serum TRH-LI or urinary aTRH-LI. In conclusion, the TRH-like peptide <EEP-NH2 is present in rat serum and is excreted into the urine. Moreover, <EEP-NH2 in serum and urine is not derived from rat food and is probably not of pituitary origin. Journal of Endocrinology (1997) 153, 411–421


1991 ◽  
Vol 280 (2) ◽  
pp. 533-539 ◽  
Author(s):  
G Reiser ◽  
R Schäfer ◽  
F Donié ◽  
E Hülser ◽  
M Nehls-Sahabandu ◽  
...  

A photolabile arylazido analogue of Ins(1,3,4,5)P4 selectively substituted at the 1-phosphate group was synthesized by coupling 2-aminoethanol(1)-1-phospho-D-myo-inositol 4,5-bisphosphate with N-hydroxysuccinimidyl-4-azidosalicylic acid [Schäfer, Nehls-Sahabandu, Grabowsky, Dehlinger-Kremer, Schulz & Mayr (1990) Biochem. J. 272, 817-825] and subsequently phosphorylating the product by bovine brain Ins(1,4,5)P3 3-kinase. The product, N-(4-azidosalicyl)-aminoethanol(1)-1-phospho-D-myo-inositol 3,4,5-trisphosphate [AsaIns(1,3,4,5)P4] was radioiodinated and purified by anion-exchange chromatography. AsaIns(1,3,4,5)P4 bound to a high-affinity Ins(1,3,4,5)P4 receptor from pig cerebellum with an affinity only 3-fold lower than that of Ins(1,3,4,5)P4. Photoirradiation of 125I-AsaIns(1,3,4,5)P4 in the presence of the receptor preparation revealed that the radioactive label was specifically associated with a protein band of apparent molecular mass 42 kDa, which Donié & Reiser [(1991) Biochem. J. 275, 453-457] had previously tentatively assigned to the Ins(1,3,4,5)P4 receptor protein. The radioactive label was displaced from the receptor when the binding reaction with 125I-AsaIns(1,3,4,5)P4 was carried out in the presence of 5 microM-Ins(1,3,4,5)P4.


1995 ◽  
Vol 108 (3) ◽  
pp. 1083-1092 ◽  
Author(s):  
A. Vassilev ◽  
M. Kimble ◽  
C.D. Silflow ◽  
M. LaVoie ◽  
R. Kuriyama

A new member of the tubulin superfamily, gamma-tubulin, is localized at microtubule-organizing centers (MTOCs) in a variety of organisms. Chlamydomonas cDNA coding for the full-length sequence of gamma-tubulin was expressed in insect ovarian Sf9 cells using the baculovirus expression system. Approximately half of the induced 52 kDa gamma-tubulin was recovered in the supernatant after centrifugation of Sf9 cell lysates at 18,000 g for 15 minutes. When the cell supernatant was analyzed by FPLC on a Superdex 200 sizing column, Chlamydomonas gamma-tubulin separated into two major peaks. The lagging peak contained a monomeric form of gamma-tubulin with a sedimentation coefficient of 2.5 S, which interacted with the Superdex column in a salt-dependent manner. The leading peak, with an apparent molecular mass of 900 kDa, corresponded to a molecular chaperonin complex, and TCP1 chaperonin released folded gamma-tubulin polypeptide from the complex in the presence of MgATP. The released gamma-tubulin monomers were capable of binding to microtubules in vitro and biochemical quantities of active monomers were further purified using a combination of size-exclusion and ion-exchange column chromatography. The endogenous Sf9 cell gamma-tubulin migrated faster than Chlamydomonas gamma-tubulin with an apparent molecular mass of 49 kDa on gels. Analyses on gel filtration and sucrose density gradient centrifugation showed that, while overexpressed Chlamydomonas gamma-tubulin was present in a monomeric form, endogenous gamma-tubulin from Sf9 and HeLa cells exists as a dimer. These results may suggest the possibility that gamma-tubulin could form a heterodimer with hitherto unknown molecule(s).


2020 ◽  
Vol 10 (8) ◽  
pp. 2648 ◽  
Author(s):  
Paolina Lukova ◽  
Mariana Nikolova ◽  
Emmanuel Petit ◽  
Redouan Elboutachfaiti ◽  
Tonka Vasileva ◽  
...  

The aim of the present study was to evaluate the prebiotic potential of Plantago major L. leaves water-extractable polysaccharide (PWPs) and its lower molecular fractions. The structure of PWPs was investigated by high pressure anion exchange chromatography (HPAEC), size exclusion chromatography coupled with multi-angle laser light scattering detector (SEC-MALLS) and Fourier-transform infrared (FTIR) spectroscopy. The chemical composition and monosaccharide analyses showed that galacturonic acid was the main monosaccharide of PWPs followed by glucose, arabinose, galactose, rhamnose and xylose. FTIR study indicated a strong characteristic absorption peak at 1550 cm−1 corresponding to the vibration of COO− group of galacturonic acid. The PWPs was subjected to hydrolysis using commercial enzymes to obtain P. major low molecular fraction (PLM) which was successively separated by size exclusion chromatography on Biogel P2. PWPs and PLM were examined for in vitro prebiotic activity using various assays. Results gave evidence for changes in optical density of the bacteria cells and pH of the growth medium. A heterofermentative process with a lactate/acetate ratio ranged from 1:1 to 1:5 was observed. The ability of PLM to stimulate the production of certain probiotic bacteria glycohydrolases and to be fermented by Lactobacillus sp. strains was successfully proved.


1998 ◽  
Vol 333 (3) ◽  
pp. 839-845 ◽  
Author(s):  
Vivienne FOLEY ◽  
David SHEEHAN

Two similar glutathione S-transferases (GSTs), which do not bind to glutathione– or S-hexylglutathione–agarose affinity resins, have been purified from the yeast Yarrowia lipolytica. An approx. 400-fold purification was obtained by a combination of DEAE-Sephadex, phenyl-Sepharose, hydroxyapatite and Mono-Q anion-exchange chromatography. The native molecular mass of both proteins was estimated as approx. 110 kDa by both Superose-12 gel-filtration chromatography and non-denaturing electrophoresis. SDS/PAGE indicated a subunit mass of 50 kDa. Reverse-phase HPLC of purified proteins gave a single, well-resolved, peak, suggesting that the proteins are homodimers. Identical behaviour on HPLC, native electrophoresis and SDS/PAGE, N-terminal sequencing, sensitivity to a panel of inhibitors and identical specific activities with 1-chloro-2,4-dinitrobenzene as substrate suggest that the two isoenzymes are very similar. The enzymes do not immunoblot with antisera to any of the main GST classes, and N-terminal sequencing suggests no clear relationship with previously characterized enzymes, such as that of the fungus, Phanerochaete chrysosporium [Dowd, Buckley and Sheehan (1997) Biochem. J. 324, 243–248]. It is possible that the two isoenzymes arise as a result of post-translational modification of a single GST isoenzyme.


1994 ◽  
Vol 304 (3) ◽  
pp. 693-698 ◽  
Author(s):  
L W J Klomp ◽  
L van Rens ◽  
G J Strous

Gastric mucin plays an important role in the protection of the stomach wall from chemical, microbiological and mechanical damage. We have previously isolated human gastric mucus glycoproteins and raised a polyclonal antiserum against these macromolecules. This antiserum specifically reacted with gastric mucins in immunoblotting experiments and stained mucous granules at the apical side of gastric surface epithelial cells. A similar staining pattern was obtained after incubation with an antiserum against rat gastric mucin. Next we used the antiserum in pulse-chase experiments of human stomach tissue explants. After short labelling periods with [35S]methionine and [35S]cysteine, the antiserum reacted with a polypeptide with an apparent molecular mass of approx. 500 kDa as determined by SDS/PAGE, which was converted after 90 min into a heterogeneous high-molecular-mass glycoprotein. This high-molecular-mass form, but not the 500 kDa polypeptide, was detectable in the culture medium after 2 h. This strongly suggests that the 500 kDa polypeptide is the precursor of the purified gastric mucin. Analysis of pulse-chase experiments by non-reducing SDS/PAGE revealed that the precursors form disulphide-linked oligomers early in biosynthesis, before the addition of O-linked sugars. After preincubation with the N-glycosylation inhibitor, tunicamycin, the apparent molecular mass of the precursor decreased marginally but consistently, indicating that N-linked glycan chains are present on the mucin precursor.


Holzforschung ◽  
2004 ◽  
Vol 58 (1) ◽  
pp. 97-104 ◽  
Author(s):  
B. Saake ◽  
S. Lebioda ◽  
J. Puls

Abstract Four methyl cellulose samples in the degree of substitution range from 0.5 to 2.0 were characterised by combination of different analytical methods. Samples were analysed regarding their partial degree of substitution by hydrolysis and anion exchange chromatography with pulsed amperometric detection. For calibration of the chromatographic system, standard substances were isolated by preparative HPLC and their structure was confirmed by 13C-NMR spectroscopy. For two methyl cellulose samples per-acetylation and 13C-NMR with inverse gated decoupling was carried out for comparison with the chromatographic analysis. Endoglucanase fragmentation of methyl celluloses was performed and water-soluble and insoluble fractions were analysed separately. A preparative size exclusion chromatography system for enzymatic-degraded water-soluble methyl cellulose was developed and the molar masses of the individual fractions were examined by analytical size exclusion chromatography. By combination of endoglucanase fragmentation, preparative chromatography, hydrolysis and anion exchange chromatography an approach for the analysis of the substitutent distribution along the polymeric chain of water-soluble methyl cellulose could be established.


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