scholarly journals Studies on carbohydrate-metabolizing enzymes. 11. The hydrolysis of lichenin by enzyme preparations from malted barley and Rhizopus arrhizus

1964 ◽  
Vol 90 (3) ◽  
pp. 596-602 ◽  
Author(s):  
WL Cunningham ◽  
DJ Manners
Keyword(s):  
Rhizopus Arrhizus ◽  
Metabolizing Enzymes ◽  
Enzyme Preparations ◽  
Hydrolysis Of

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.

Influence of dopamine on cyclic nucleotide enzymes in bovine retinal membrane fractions

1993 ◽  
Vol 10 (6) ◽  
pp. 991-996 ◽  
Author(s):  
Ari Sitaramayya ◽  
Lorraine Lombardi ◽  
Alexander Margulis
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Cyclic Nucleotide ◽  
D2 Receptors ◽  
D1 Receptors ◽  
Metabolizing Enzymes ◽  
D2 Agonist ◽  
Hydrolysis Of ◽  
Cyclic Amp Synthesis

AbstractDopamine is a major neurotransmitter and neuromodulator in vertebrate retina. Although its pharmacological and physiological actions are well understood, the biochemical mechanisms of its signal transduction are less clear. Acting via D1 receptors, dopamine was shown to increase cyclic AMP levels in intact retina and to activate adenylate cyclase in retinal homogenates. The action via activation of D2 receptors is controversial: it was reported to decrease cyclic AMP levels in intact retina but inhibition of cyclase could not be demonstrated in retinal homogenates; also it was reported to activate rod outer segment cyclic GMP phosphodiesterase in vitro but did not decrease cyclic GMP levels in aspartate-treated retinas. We made an attempt to fractionate bovine retinal membranes and to investigate the effects of dopamine, via Dl and D2 receptors, on the synthesis and hydrolysis of cyclic AMP and cyclic GMP. Activation of cyclic AMP synthesis was noted in all fractions, but no effects were evident on cyclic nucleotide hydrolysis or cyclic GMP synthesis in any fraction. Also, D2 agonist did not inhibit cyclic AMP synthesis. These observations suggest that D2 receptors may not be directly coupled to cyclic nucleotide metabolizing enzymes in bovine retina.

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 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.

Toxicokinetics and Hydrolysis of Artelinate and Artesunate in Malaria-Infected Rats

2005 ◽  
Vol 24 (4) ◽  
pp. 241-250 ◽  
Author(s):  
Qigui Li ◽  
Lisa H. Xie ◽  
Yuanzheng Si ◽  
Elaine Wong ◽  
Ravi Upadhyay ◽  
...  
Keyword(s):  
Drug Exposure ◽  
Enterohepatic Circulation ◽  
Metabolizing Enzymes ◽  
Antimalarial Agents ◽  
Elimination Half ◽  
Conversion Rates ◽  
Daily Dose ◽  
Exposure Levels ◽  
Distribution Studies ◽  
Hydrolysis Of

Comparative toxicokinetic (TK) and hydrolysis studies of intravenously administered two new antimalarial agents, artelinate (AL) and artesunate (AS), were performed in malaria-infected rats using three daily equimolar doses (96 μmoles/kg). The TK evaluation was related to select one drug for severe malaria treatment in U.S. Army. Drug concentration of AS with daily dose of 36.7 mg/kg was one-third less on day 3 than on day 1, which resembled its active metabolite, dihydroartemisinin (DHA), suggesting an autoinduction of hepatic drug-metabolizing enzymes for AS. The results were similar to other artemisinin drugs, but not for AL. TK parameters of AL were very comparable from day 1 to day 3 at same AS molecular dose at 40.6 mg/kg. AS is the prodrug of DHA with the DHA/AS ratio of 5.26 compared to the ratio of 0.01 for DHA/AL. Other TK parameters revealed that the total AUC1–3 days (84.4 μg · h ml−1) of AL was fivefold higher than that of AS (15.7 mu;g h ml−1 of AS plus DHA). The elimination half-life of AL (7.1 h) was much longer than that of AS (0.36 h) or DHA (0.72 h). The remarkable alteration of the TK shape of AL may be caused by poor conversion rates to DHA and an enterohepatic circulation, which is confirmed by the present TK and tissue distribution studies. Compared to AS, higher drug exposure levels and longer exposure time of AL in the rat blood may be the cause of its increased toxicity.

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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