scholarly journals The hydrolysis of glycosyl fluorides by glycosidases

1967 ◽  
Vol 105 (2) ◽  
pp. 669-672 ◽  
Author(s):  
J. E. G. Barnett ◽  
W. T. S. Jarvis ◽  
K A Munday
Keyword(s):  
Helix Pomatia ◽  
Enzyme Preparations ◽  
Intestinal Juice ◽  
Hydrolysis Of ◽  
Specific Inhibitors

1. α-d- and β-d-Glucopyranosyl, α-d- and β-d-galactopyranosyl, α-d-mannopyranosyl and α-d-xylopyranosyl fluorides were hydrolysed specifically by the respective glycosidases from several sources. 2. Use of specific inhibitors with a mixture of glycosidases from Helix pomatia intestinal juice showed that each glycosyl fluoride was hydrolysed only by the respective glycosidase. α-d-Glucopyranosidase and α-d-xylopyranosidase activities were shown to be due to different enzymes. 3. Partially purified enzyme preparations containing only one of the glycosidase activities hydrolysed only the corresponding glycosyl fluoride. 4. The configuration at C-1 of α-d-mannopyranosyl fluoride was confirmed since it was hydrolysed by an α-d-mannosidase preparation that contained no detectable β-d-mannosidase activity. 5. An attempt to prepare o-nitrophenyl β-d-mannopyranoside led only to o-nitrophenyl α-d-mannopyranoside.

Hydrolysis of steroid glucuronides with beta-glucuronidase preparations from bovine liver, Helix pomatia, and E. coli.

1977 ◽  
Vol 23 (3) ◽  
pp. 532-535 ◽  
Author(s):  
V Graef ◽  
E Furuya ◽  
O Nishikaze
Keyword(s):  
Helix Pomatia ◽  
Bovine Liver ◽  
Enzymic Activity ◽  
Enzyme Preparations ◽  
E Coli ◽  
Rate Of Hydrolysis ◽  
Polystyrene Resin ◽  
Good For ◽  
Hydrolysis Of ◽  
Urinary Steroid

Abstract We determined the enzymic activity of beta-glucuronidase preparations from bovine liver, Helix pomatia, and Escherischia coli with steroid glucuronides and nonsteroid glucuronides as substrates. We also studied the effect of Na2SO4 on the enzymic hydrolysis of several substrates with the three preparations of beta-glucuronidase. Na2SO4 increases the rate of hydrolysis of all substrates with beta-glucuronidase from bovine liver. Hydrolysis of a steroid glucoronide with beta-glucuronidase from Helix pomatia and E. coli is inhibited by Na2SO4. None of the three enzyme preparations gives complete hydrolysis of urinary steroid conjugates, because urine contains inhibitors, which can be removed by absorption chromatography of the urine on a column of neutral polystyrene resin Amberlite XAD-2. But when Amberlite XAD-2 is not used, hydrolysis of urinary glucuronides of androsterone, etiocholanolone, pregnanediol, estriol, and 17-hydroxycorticosteroids proves that, given an incubation time of 24 h, the beta-glucuronidase preparation from bovine liver, in the presence of Na2SO4, is suited for determining all of the above steroids except esriol; the preparation from Helix pomatia is good for determining estriol and 17-hydroxycorticosteroids; the preparation from E. coli is good for determining androsterone, 17-hydroxycorticosteroids, and especially estriol, the glucuronide, of which is maximally hydrolyzed in 2 h.

A Qualitative Gas Chromatographic Analysis of Substituted 5,6-Dihydroxyindoles from the Urine of Patients with Melanoma

1981 ◽  
Vol 67 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Stanislav Pavel ◽  
Frits A. J. Muskiet ◽  
Alena Budešínská ◽  
Jirí Duchon
Keyword(s):  
Ethyl Acetate ◽  
Chromatographic Analysis ◽  
Helix Pomatia ◽  
Nitrogen Atmosphere ◽  
Spectrometric Analysis ◽  
Gas Chromatographic Analysis ◽  
Indolic Compounds ◽  
Hydrolysis Of ◽  
Ethyl Acetate Extracts ◽  
Chromatographic Mass

A qualitative gas chromatographic analysis of trimethylsilylated ethyl acetate extracts of melanotic urine revealed 5 indolic compounds, which have been identified as substituted 5,6-dihydroxyindoles. Ethyl acetate extracts of melanotic urines at pH 2.0 contained isomeric 5-hydroxy-6-methoxy and 6-hydroxy-5-methoxy-indolyl-2-carboxylic acids which were not separable under the conditions used. A careful hydrolysis of melanotic urine with a Helix pomatia preparation followed by extraction at pH 6.5 in a nitrogen atmosphere released 3 additional indolic compounds from their conjugated form. Using gas chromatographic-mass spectrometric analysis they were identified as 5-hydroxy-6-methoxy, 6-hydroxy-5-methoxyindole and 5,6-dihydroxyindole.

SOME ASPECTS OF THE ENZYMIC HYDROLYSIS OF URINARY 17-KETOSTEROID CONJUGATES

1960 ◽  
Vol 38 (1) ◽  
pp. 769-776
Author(s):  
R. Hobkirk ◽  
J. J. Cohen
Keyword(s):  
Liver Enzymes ◽  
Striking Difference ◽  
Degree Of Hydrolysis ◽  
Enzyme Preparations ◽  
Bacterial Preparation ◽  
Bacterial Enzyme ◽  
The Difference ◽  
Normal Urine ◽  
High Degree ◽  
Hydrolysis Of

Four enzyme preparations containing β-glucuronidase, of bacterial, mammalian, and molluscan origin, have been shown to be equally effective in liberating 17-ketosteroids (17-KS) of the 5β-(etiocholane) configuration in normal urine. The bacterial preparation releases steroids of the 5α-(androstane) configuration more rapidly than do the molluscan enzymes and with much greater ease than does the liver enzyme. In view of the data obtained it seems unlikely that the striking difference between the bacterial and liver enzymes can be due to the hydrolysis of some labile conjugate, such as sulphate, by the former and not by the latter. Possibilities that the difference is due to the hydrolysis of an unknown type of urinary conjugate by the bacterial preparation, or to the low specificity of the bacterial β-glucuronidase, are discussed. The high degree of hydrolysis of 17-KS conjugates by the bacterial enzyme followed by solvolysis suggests this as a most useful hydrolytic procedure.

SOME ASPECTS OF THE ENZYMIC HYDROLYSIS OF URINARY 17-KETOSTEROID CONJUGATES

1960 ◽  
Vol 38 (7) ◽  
pp. 769-776 ◽  
Author(s):  
R. Hobkirk ◽  
J. J. Cohen
Keyword(s):  
Liver Enzymes ◽  
Striking Difference ◽  
Degree Of Hydrolysis ◽  
Enzyme Preparations ◽  
Bacterial Preparation ◽  
Bacterial Enzyme ◽  
The Difference ◽  
Normal Urine ◽  
High Degree ◽  
Hydrolysis Of

Four enzyme preparations containing β-glucuronidase, of bacterial, mammalian, and molluscan origin, have been shown to be equally effective in liberating 17-ketosteroids (17-KS) of the 5β-(etiocholane) configuration in normal urine. The bacterial preparation releases steroids of the 5α-(androstane) configuration more rapidly than do the molluscan enzymes and with much greater ease than does the liver enzyme. In view of the data obtained it seems unlikely that the striking difference between the bacterial and liver enzymes can be due to the hydrolysis of some labile conjugate, such as sulphate, by the former and not by the latter. Possibilities that the difference is due to the hydrolysis of an unknown type of urinary conjugate by the bacterial preparation, or to the low specificity of the bacterial β-glucuronidase, are discussed. The high degree of hydrolysis of 17-KS conjugates by the bacterial enzyme followed by solvolysis suggests this as a most useful hydrolytic procedure.

Blending of cellulolytic enzyme preparations from different fungal sources for improved cellulose hydrolysis by increasing synergism

RSC Advances ◽  
2014 ◽  
Vol 4 (84) ◽  
pp. 44726-44732 ◽  
Author(s):  
Mukund Adsul ◽  
Bhawna Sharma ◽  
Reeta Rani Singhania ◽  
Jitendra Kumar Saini ◽  
Ankita Sharma ◽  
...  
Keyword(s):  
Wheat Straw ◽  
Cellulose Hydrolysis ◽  
Cellulolytic Enzyme ◽  
Enzyme Preparations ◽  
Fungal Enzyme ◽  
Enzyme Cocktail ◽  
Different Types ◽  
Hydrolysis Of

A prepared enzyme cocktail from different fungal enzyme preparations increases the hydrolysis of avicel/wheat straw by increasing synergism between the same or different types of cellulases.

scholarly journals Development of a concept for the production of wheat snacks with the elimination of gluten by the biocatalysis

2021 ◽  
Vol 82 (4) ◽  
pp. 77-83
Author(s):  
A. Y. Sharikov ◽  
E. N. Sokolova ◽  
M. V. Amelyakina ◽  
T. V. Yuraskina ◽  
V. V. Ivanov ◽  
...  
Keyword(s):  
Protein Modification ◽  
Raw Materials ◽  
Amino Acid Sequences ◽  
Practical Implementation ◽  
Specific Amino Acid ◽  
Enzyme Preparations ◽  
Molecular Weights ◽  
Enzyme Systems ◽  
Antigenic Properties ◽  
Hydrolysis Of

The increase in the number of cases of allergic reactions and celiac disease is an important problem. The solution to this problem is the search and development of relevant and effective ways to eliminate gluten. Specific amino acid sequences glutamine and proline determine the resistance to protease hydrolysis of the structural domains of gluten fractions. The analysis of the literature data showed that an alternative to the gluten-free diet is the use of biotechnological methods for modifying ingredients containing gluten. Such methods include the use of leavens on the base of lactic acid bacteria or enzyme preparations containing peptidases specific to gluten biocatalysis. In addition, the pretreatment of raw materials by extrusion cooking contributes to an increase in the degree of gluten hydrolysis. The effect of the thermoplastic extrusion and various enzyme systems containing proteases, amylolytic, cellulolytic and hemicellulolytic enzymes on the changes in the molecular weights of wheat protein fractions was studied. It was found that extrusion as a factor of protein modification significantly affects the proteolysis of wheat proteins using enzyme systems of different substrate specificity. The most effective hydrolysis was shown by the use of a complex enzyme preparation Amyloprotoorizin. including The effect was also noted after bioconversion of non-extruded wheat. An algorithm for the technology of wheat snacks based on the processes of extrusion and biocatalysis of proteins with specific proteases for the elimination of gluten is devepoped. The practical implementation of the technology will make it possible to obtain ready-to-eat snacks, which will be investigated for the preservation or elimination of antigenic properties during clinical trials.

scholarly journals HYDROLYTIC REGULATION OF COMPONENT PROPERTIES

2020 ◽  
Vol 6 (444) ◽  
pp. 23-28
Author(s):  
V. A. Asafov ◽  
◽  
N. L. Tankova ◽  
E. L. Iskakova ◽  
T. N. Golovach ◽  
...  
Keyword(s):  
Raw Materials ◽  
Farm Animals ◽  
Animal Origin ◽  
Enzyme Preparations ◽  
Global Trends ◽  
Antigenic Activity ◽  
The Republic ◽  
Protein Components ◽  
Hydrolysis Of ◽  
Plant Sources

. The article provides an assessment of the dairy farming need in the Russian Federation and the Republic of Belarus in calves feed. The main global trends aimed at providing young animals with high-quality food means are considered. Various variants of directed hydrolysis of calf milk replacer (CMR) protein components intended for feeding young animals in the first months of life are analyzed. The possibilities of reducing the soy proteins antigenic activity, which are widely used at present in the CMR formulations for feeding young farm animals, are discussed. The results of experimental work and patents are presented, which describe the most widely used approaches to the production of enzymatic hydrolysates of proteins with desired properties, as well as the assessment of their biological activity and immunochemical properties. The issues of using various enzyme preparations of bacterial, fungal and animal origin for hydrolysis of colostrum proteins and plant sources of protein raw materials for the CMR production are considered.

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