Separation and characterization of an α-glucosidase and maltase from Bacillus amyloliquefaciens

1985 ◽  
Vol 31 (8) ◽  
pp. 670-674 ◽  
Author(s):  
William M. Fogarty ◽  
Catherine T. Kelly ◽  
Sunil K. Kadam

A novel α-glucosidase and a maltase were isolated from Bacillus amyloliquefaciens. The formation of both enzymes was induced by trehalose, sucrose, or lactose in the growth medium. Trehalose is by far the most efficient inducer of both systems. The α-glucosidase and maltase were separated and purified by ion-exchange chromatography on DEAE Bio-Gel A. Purified α-glucosidase hydrolysed p-nitrophenyl-α-D-glucoside, isomaltose, and isomaltotriose but sucrose, maltose, or related saccharides were not attacked. β-Glucosides and polymeric glucosides were not degraded. The optimum temperature for α-glucosidase activity was 40 °C and its pH optimum was 5.3. The molecular weight and isoelectric point (pI) of the enzyme were 27 000 and 4.6, respectively. Purified maltase attacked maltose and sucrose, while maltotriose and melezitose were hydrolysed at slower rates and p-nitrophenyl-α-D-glucoside was not degraded. Other properties of the maltase were as follows: optimum temperature for activity, 30 °C; pH optimum, 6.5; molecular weight, 64 000; and pI, 4.7.

1976 ◽  
Vol 29 (2) ◽  
pp. 11 ◽  
Author(s):  
Robert C Marshall ◽  
JM Gillespie

The present paper continues the study of the reduced and S-carboxymethylated high-sulphur proteins from mouse hair. Fractions have been obtained in a substantially purified form by fractional precipitation with ammonium sulphate at pH 6, followed by ion exchange chromatography on cellulose phosphate at pH 2�6. Approximately 80% by weight of the high-sulphur proteins fall into the ultra-high-sulphur category (carboxymethyicysteine content greater than 26 residues per 100 residues), and they cover a molecular weight range of 17000-28000. The components show a remarkable diversity in amino acid composition; for example the contents of arginine and glycine each vary by about 3 : 1. The remainder of the proteins contain 17-20 residues per 100 residues of carboxymethyicysteine, are smaller in size (molecular weight 11 500), and also show great diversity in overall amino acid composition.


1985 ◽  
Vol 63 (11) ◽  
pp. 1160-1166 ◽  
Author(s):  
Pierre Gondé ◽  
Robert Ratomahenina ◽  
Alain Arnaud ◽  
Pierre Galzy

The exocellular enzyme β-glucosidase of Candida molischiana was studied. This strain is able to ferment soluble cellodextrins. The enzyme was partially purified by ion-exchange chromatography and gel filtration. The molecular weight of this enzyme was 120 000; its optimum pH was between 4 and 4.5 and its optimum temperature was 60 °C. This enzyme was active against different soluble glucosides and was inhibited by p-chloromercuribenzoate, gluconolactone, and glucose. A "glucosyltransferase" activity appeared in the presence of ethanol. The biosynthesis of the enzyme was constitutive but repressed by glucose.


1971 ◽  
Vol 25 (03) ◽  
pp. 580-589 ◽  
Author(s):  
M Uszynski ◽  
U Abildgaard

SummaryProcedures for the separation of two inhibitors of the activation of plasminogen to plasmin by urokinase are described. Tissue thromboplastin was removed by adsorption to Al(0H)3 gel followed by ultracentrifugation. Plasminogen, plasminogen activator, a coagulation inhibitor and hemoglobin were removed by ion exchange chromatography (CM- or DEAE-Sephadex with NaCl gradients). The minor UK inhibitor is a relative basic protein with a pI of about 5.8. The major inhibitor was purified further by isoelectric focusing, preparative electrophoresis in polyacrylamide gel, and gel filtration. This inhibitor has α1-motility, the pI is about 5.2, and the molecular weight about 100,000. It inactivates urokinase progressively, but does not inhibit streptokinase, plasmin or thrombin.


1993 ◽  
Vol 48 (7-8) ◽  
pp. 563-569 ◽  
Author(s):  
Nariyuki Ishikura ◽  
Zhi-qing Yang ◽  
Susumu Teramoto

Two different O-glucosyl transferases (F3GT and F7GT ) catalyzing the transfer of ᴅ-glucose from UDP-ᴅ-glucose to the 3 and 7 positions of flavonol, respectively, were isolated from the young leaves of Paederia scandens var. mairei. F3GT and F7GT, which were recovered in about a 1:1 ratio in the activity, were purified by about 140- and 136-fold, respectively, by precipitation with ammonium sulfate followed by ion exchange chromatography and chromatofocusing. F3GT and F7GT both had a pH optimum of 7.5 in Tris-HCl buffer, and an Mr of 43 kDa. Neither F3GT nor F7GT had a Mg2+ requirement. Both were inhibited by each 1 mᴍ of Zn2+, Cu2+, N-ethylmaleimide and p-chloromercuribenzoate, and both were stimulated by 14 mᴍ 2-M E . F3GT and F7GT were different from each other in having an isoelectric point (pI) at pH 5.12 and 4.50, respectively. F3GT mediated the transfer of D-glucose exclusively to the 3-hydroxyl group of kaempferol and some flavonols, but neither the 7-O-glucosides nor the 3-O-glucosides of their flavonols were able to accept D-glucose. On the other hand, F7GT mediated the transfer of D-glucose exclusively to the 7-hydroxyl group of kaempferol and some flavonols, and in addition, the 3-O -glucosides of kaempferol and quercetin were able to accept D-glucose thoughn less efficiently. Consequently, the possibility of sequential steps of 3-O- and then 7-O-glucosylations of flavonols to give the 3,7-di-O-glucoside was discussed.


1994 ◽  
Vol 49 (1-2) ◽  
pp. 70-78 ◽  
Author(s):  
Ulrike Strohmeier ◽  
Christian Gerdes ◽  
Wolfgang Lockau

Soluble extracts of the cyanobacterium Anabaena variabilis ATCC 29413 and an engineered mutant that lacks an intracellular protease cleaving after Lys and Arg (Maldener, Lockau, Cai, and Wolk, Mol. Gen. Genet. 225, 113-120 (1991)) were separated by ion exchange chromatography, and protease profiles determined using azocasein, Nα-benzoyl-ᴅ,ʟ arginine- 4-nitroanilide and N-carbobenzoxy-glycyl-ʟ-proline-4-nitroanilide as substrates. A second enzyme cleaving at the carboxyl side of lysine and arginine, and a prolyl endopeptidase were detected, enriched and characterized. Both proteolytic enzymes appear to be located in the periplasm.


Parasitology ◽  
1994 ◽  
Vol 109 (1) ◽  
pp. 113-118 ◽  
Author(s):  
C. Carmona ◽  
S. McGonigle ◽  
A. J. Dowd ◽  
A. M. Smith ◽  
S. Coughlan ◽  
...  

SUMMARYA dipeptidylpeptidase (DPP) was isolated from Fasciola hepatica by gel-filtration and ion-exchange chromatography. The exoproteinase is secreted by newly excysted juveniles, immature and mature flukes. The liver fluke DPP is a serine proteinase of molecular weight > 200 kDa and differs from previously characterized mammalian DPPs in its substrate preference and susceptibility to inactivation by inhibitors. The parasite DPP may function in the latter stages of the proteolytic digestion of host macromolecules. In this manner, the enzyme may be important in providing the parasite with dipeptides that could be absorbed through the intestine as nutrient.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Rinky Rajput ◽  
Richa Sharma ◽  
Rani Gupta

An extracellular keratinase from Bacillus pumilus KS12 was purified by DEAE ion exchange chromatography. It was a 45 kDa monomer as determined by SDS PAGE analysis. It was found to be an alkaline, serine protease with pH and temperature optima of 10 and 60C, respectively. It was thiol activated with two- and eight-fold enhancement in presence of 10 mM DTT and β-mercaptoethanol, respectively. In addition, its activity was stimulated in the presence of various surfactants, detergents, and oxidizing agents where a nearly 2- to 3-fold enhancement was observed in presence of H2O2 and NaHClO3. It hydrolyzed broad range of complex substrates including feather keratin, haemoglobin, fibrin, casein,and α-keratin. Analysis of amidolytic activity revealed that it efficiently cleaved phenylalanine → leucine → alanine- p-nitroanilides. It also cleaved insulin B chain between Val2- Asn3, Leu6-Cys7 and His10-Leu11 residues.


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