Menadione reductase from Clostridium tyrobutyricum

1980 ◽  
Vol 26 (3) ◽  
pp. 324-329 ◽  
Author(s):  
H. Petitdemange ◽  
R. Marczak ◽  
G. Raval ◽  
R. Gay
Keyword(s):  
Molecular Weight ◽  
Coenzyme Q ◽  
Analysis Data ◽  
Carbon Chain ◽  
Clostridium Tyrobutyricum ◽  
Enzymatic Analysis ◽  
Prosthetic Group ◽  
Ping Pong ◽  
Enzymatic Reduction ◽  
Quinoid Structure

Menadione reductase (EC 1.6.99.2) has been purified 67-fold from Clostridium tyrobutyricum extracts. The molecular weight was found to be 60 000 and the prosthetic group was identified as FMN on the basis of the enzymatic analysis data. The binding of FMN to the menadione dehydrogenase apoenzyme was relatively weak with an apparent Km value of 2.5 × 10−6 M.The enzyme exhibited group substrate specificity for compounds with a quinoid structure; naphthoquinones and benzoquinones without long carbon chain substituents were the most active. The reactivity of the enzyme with vitamin K1, coenzyme Q6, and cytochrome c was negligible and, with 2,6-dichlorophenol indophenol, relatively low.It was shown that the enzymatic reduction of menadione with the participation of either NADH or NADPH takes place by a "Ping-Pong" mechanism. The enzyme catalyzed the oxidation of NADH and NADPH at equal rates and was inhibited by dicumarol and p-chloromercuribenzoate.

scholarly journals Biodegradation of low molecular weight polyacrylamide under aerobic and anaerobic conditions: effect of the molecular weight

2020 ◽  
Vol 81 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Wenzhe Song ◽  
Yu Zhang ◽  
Amir Hossein Hamidian ◽  
Min Yang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Carbon Chain ◽  
Anaerobic Treatment ◽  
Low Molecular Weight ◽  
Amino Groups ◽  
Molecular Weights ◽  
Weight One ◽  
Hydrolysis Of ◽  
Aerobic And Anaerobic

Abstract The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0–52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2–17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45–7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76–5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.

Acid Proteases From Species of Mucor: Molecular Weight of Mucor miehei Protease From Amino Acid Analysis Data

1973 ◽  
Vol 51 (12) ◽  
pp. 1638-1646 ◽  
Author(s):  
W. S. Rickert ◽  
J. R. Elliott
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Weight Function ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Amino Acid Analysis ◽  
Analysis Data ◽  
Improved Method ◽  
Mucor Miehei ◽  
A Value

An improved method for the isolation of Mucor miehei protease which utilizes a diafiltration cell has been used to obtain a highly purified protein in gram quantities and yields of about 80%. Based on a modified molecular weight function and data from amino acid analysis, a value of 41 800 for the molecular weight of the glycoprotein was established and some modification to the published amino acid composition was made. These results suggest that Mucor miehei protease is distinctly different from the two other acid proteases which are also produced by species of Mucor.

scholarly journals The purification and properties of butyryl-coenzyme A dehydrogenase from Peptostreptococcus elsdenii

1971 ◽  
Vol 125 (3) ◽  
pp. 879-887 ◽  
Author(s):  
Paul C. Engel ◽  
V. Massey
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Simple Procedure ◽  
Potassium Bromide ◽  
Prosthetic Group ◽  
Pig Liver ◽  
Peak Absorption ◽  
Purification And Properties ◽  
Green Form ◽  
Spectrophotometric Titrations

Butyryl-CoA dehydrogenase prepared by a simple procedure from Peptostreptococcus elsdenii has a molecular weight of approx. 150000. The enzyme has FAD as its prosthetic group. The amino acid analysis is reported. This enzyme, like most of the corresponding mammalian ones, is green. The absorption band at 710nm can be abolished irreversibly by dithionite reduction and air reoxidation; it can be abolished reversibly by phenylmercuric acetate or potassium bromide. The enzyme as isolated appears to be a mixture of a green and a yellow form, both of which are active. This view is supported by the variable ‘greenness’ of different preparations and the biphasic curve obtained in anaerobic spectrophotometric titrations with dithionite. It can be calculated from the titration results that fully green enzyme would have a peak-to-peak absorption ratio (E710/E430) as great as 0.54. The green form is much less rapidly reduced by dithionite than the yellow form, but is nevertheless much more readily reduced by dithionite than the enzyme from pig liver. It is also more readily reoxidized by air and shows less tendency to form a semiquinone. Treatment with sodium borohydride produces an unusual reduced species that is probably the 3,4-dihydroflavin.

scholarly journals Theoretical Prediction of Thermophysical Properties of Waste Beef Tallow Biodiesel

2020 ◽  
Author(s):  
Gokul Raghavendra Srinivasan ◽  
Ranjitha Jambulingam
Keyword(s):  
Molecular Weight ◽  
Beef Tallow ◽  
Linear Equations ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Independent Variables ◽  
Degree Of Unsaturation ◽  
Carbon Molecules ◽  
Thermo Physical Properties ◽  
Two Independent Variables

In this present study, simple linear equations were developed for predicting the thermo-physical properties of beef tallow biodiesel by considering their molecular weight and number of double bonds as two independent variables. Interestingly, molecular weight signifies as a function of carbon chain length and number of carbon molecules in it whereas numbers of double bond signifies the degree of unsaturation.

scholarly journals Theoretical Prediction of Thermophysical Properties of Waste Beef Tallow Biodiesel

2020 ◽  
Author(s):  
Gokul Raghavendra Srinivasan ◽  
Ranjitha Jambulingam
Keyword(s):  
Molecular Weight ◽  
Beef Tallow ◽  
Linear Equations ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Independent Variables ◽  
Degree Of Unsaturation ◽  
Carbon Molecules ◽  
Thermo Physical Properties ◽  
Two Independent Variables

In this present study, simple linear equations were developed for predicting the thermo-physical properties of beef tallow biodiesel by considering their molecular weight and number of double bonds as two independent variables. Interestingly, molecular weight signifies as a function of carbon chain length and number of carbon molecules in it whereas numbers of double bond signifies the degree of unsaturation.

Low-molecular-weight heparins: Pharmacoeconomic decision modeling based on meta-analysis data

2010 ◽  
Vol 26 (3) ◽  
pp. 272-279 ◽  
Author(s):  
Edmundas Kadusevicius ◽  
Gabriele Kildonaviciute ◽  
Birute Varanaviciene ◽  
Danguole Jankauskiene
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Fixed Effects ◽  
Cost Minimization ◽  
Meta Analysis ◽  
Analysis Data ◽  
Low Molecular Weight ◽  
Decision Modeling ◽  
Low Molecular Weight Heparins ◽  
Reference Pricing

Objectives: The aim of this study was to compare efficacy, safety, and consumption of low-molecular-weight heparins with unfractionated heparin, and to develop a pharmacoeconomic decision model based on meta-analysis data.Methods: Review and meta-analysis were performed of published randomized control trials directly comparing the safety and efficacy of low-molecular-weight heparins (LMWHs)—that is, nadroparin, enoxaparin, and dalteparin—and unfractionated heparin (UFH) was performed by two reviewers using inclusion/exclusion criteria based on the research objectives. The value of fixed effects and random effects odds ratio (95 percent confidence interval) was calculated for each trial for the composite end point. Subsequently, a pharmacoeconomic decision modeling based on reference pricing methodology was implemented.Results: In comparison to UFH, all LMWHs have independently demonstrated greater safety and effectiveness. None of the LMWHs demonstrated a significant superiority over each other; therefore, the group of LMWHs was interchangeable and suitable for cost minimization analysis and reference price implementation. Being the least expensive option, dalteparin single DDD price was set as the reference. Introduction of reference pricing for LMWHs would decrease the total expenditure on LMWHs of approximately 30 percent and would result in total savings of 1.830–2.070 thousand LTL in the country of Lithuania (approximately 0.8 million USD) per year.Conclusions: The meta-analysis results of LMWHs could be used to support a policy on reference-based pricing and pharmacoeconomic decision modeling in healthcare institutions, which would allow a decrease in healthcare expenditures.

Purification and properties of crustacyanin

1966 ◽  
Vol 164 (994) ◽  
pp. 130-151 ◽  
Keyword(s):  
Molecular Weight ◽  
Quaternary Structure ◽  
Gel Filtration ◽  
Potassium Thiocyanate ◽  
Starch Gel Electrophoresis ◽  
Prosthetic Group ◽  
Reversible Dissociation ◽  
Purification And Properties ◽  
Starch Gel ◽  
Quaternary Structures

Crustacyanin, the blue carapace pigment of the common lobster Homarus gammarus (L.), has been purified and crystallized. This chromoprotein has a minimum molecular weight of 36 000 based on the content of the carotenoid prosthetic group astaxanthin. The molecular weight in gel filtration measurements is about 650 000, corresponding to some 18 molecules of astaxanthin per molecule of protein. Crustacyanin, on dialysis against water, dissociates into particles of about 35 000 molecular weight, each apparently bearing one molecule of carotenoid. The dissociation is accompanied by a shift in the principal maximum of the absorption spectrum from 633 to 595 nm and is reversed upon addition of salt. Reversible dissociation also occurs in the presence of 3 M urea, 1 M potassium thiocyanate, 10% (v/v) dioxan or 10% (v/v) acetone. When the carotenoid is removed from crustacyanin with acetone, the resul­tant apoprotein has a mean molecular weight of about 20 000. It may be resolved by starch gel electrophoresis into several components of which two predominate. Crustacyanin, indistinguishable from the native material, can be reconstituted from apoprotein and carotenoid. Evidence from the behaviour of crustacyanin and its apoprotein at surfaces indicates that the tertiary and quaternary structures of the native protein are stabilized by the carotenoid. It is suggested that the quaternary structure of crustacyanin is induced by an interaction of the carotenoid molecules of the subunits, which in turn causes a change in configuration of the protein favourable to aggregation. The result is a micelle-like structure with a hydrophobic carotenoid core.

scholarly journals Coenzyme Q10: Clinical Update and Bioavailability

2011 ◽  
Vol 16 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Ginny Bank ◽  
Daniel Kagan ◽  
Doddabele Madhavi
Keyword(s):  
Molecular Weight ◽  
Clinical Trials ◽  
Dietary Supplement ◽  
Clinical Efficacy ◽  
Coenzyme Q10 ◽  
Coenzyme Q ◽  
Health Conditions ◽  
Efficacy Trials ◽  
Large Molecular Weight ◽  
Clinical Potential

Coenzyme Q10 (CoQ 10) supplementation has been reported to be beneficial in treating a variety of health conditions and diseases, with more than 200 clinical trials investigating its use as a drug or dietary supplement. Numerous reviews of the safety and clinical potential of CoQ10 have been published. Successful treatment and efficacy is dependent on the bioavailability of CoQ 10, which is well known to be poor because of its lipophilic nature and large molecular weight. A number of recent clinical trials on CoQ 10 have investigated new formulations of CoQ10 for improvements in absorption and bioavailability. This review provides an update of clinical efficacy trials using CoQ10 and describes recent advances in formulation technology to improve the bioavailability of CoQ10. The authors also discuss a new method to improve the standards of reporting the bioavailability results of such advanced CoQ10 formulations to help clinicians and consumers make informed decisions.

Sign in / Sign up

Export Citation Format

Share Document