Acetohydroxy acid reductoisomerase of wheat

2000 ◽  
Vol 27 (5) ◽  
pp. 417 ◽  
Author(s):  
Roberta Donadini ◽  
Les Copeland
Keyword(s):  
Molecular Mass ◽  
Triticum Aestivum L ◽  
The Other ◽  
Size Exclusion ◽  
Elution Volume ◽  
Substrate Preparation ◽  
Strong Base ◽  
High Degree ◽  
Hydrolysis Of ◽  
By Products

Acetohydroxy acid reductoisomerase (EC 1.1.1.86, AHAR) was purified to a high degree from green shoots of wheat (Triticum aestivum L. cv. Vulcan). The enzyme was localised in the chloroplasts, and activity was at a maximum approximately 4 d after germination. The subunit molecular mass of wheat AHAR was 57 kD and activity of the native enzyme had an elution volume from size exclusion columns that corresponded to a molecular mass of 47 kD. The enzyme did not require the addition of Mg 2+ ions to reaction mixtures for activity. The Km values for (R,S)-2-acetolactate and (R,S)-2-aceto-2-hydroxybutyrate were 91 and 9 mM, respectively, and the corresponding maximum velocities were 430 and 451 mU mg –1 protein. The Km for NADPH was approximately 10 mM when either of the acetohydroxy acids was the other substrate. Preparation of the acetohydroxy acid substrates by hydrolysis of the parent esters in strong base led to the formation of inhibitory by-products. Racemisation of the acetohydroxy acids was detected in assay mixtures.

scholarly journals Exploring Effects of Protease Choice and Protease Combinations in Enzymatic Protein Hydrolysis of Poultry By-Products

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5280
Author(s):  
Diana Lindberg ◽  
Kenneth Aase Kristoffersen ◽  
Sileshi Gizachew Wubshet ◽  
Linn Maria Gundersen Hunnes ◽  
Marte Dalsnes ◽  
...  
Keyword(s):  
Value Creation ◽  
Product Yield ◽  
Protein Yield ◽  
Size Exclusion ◽  
Rational Approach ◽  
Major Protein ◽  
Sds Page ◽  
Stem Bromelain ◽  
Hydrolysis Of ◽  
By Products

A study of the effects of single and combined protease hydrolysis on myofibrillar versus collagenous proteins of poultry by-products has been conducted. The aim was to contribute with knowledge for increased value creation of all constituents of these complex by-products. A rational approach was implemented for selecting proteases exhibiting the most different activity towards the major protein-rich constituents of mechanically deboned chicken residue (MDCR). An initial activity screening of 18 proteases on chicken meat, turkey tendons and MDCR was conducted. Based on weight yield, size exclusion chromatography (SEC) and SDS-PAGE, stem Bromelain and Endocut-02 were selected. Studies on hydrolysis of four different poultry by-products at 40 °C, evaluated by protein yield, SEC, and SDS-PAGE, indicate that the proteases’ selectivity difference can be utilized in tailor-making hydrolysates, enriched in either meat- and collagen-derived peptides or gelatin. Three modes of stem Bromelain and Endocut-02 combinations during hydrolysis of MDCR were performed and compared with single protease hydrolysis. All modes of the protease combinations resulted in a similar approximately 15% increase in product yield, with products exhibiting similar SEC and SDS-PAGE profiles. This shows that irrespective of the modes of combination, the use of more than one enzyme in hydrolysis of collagen-rich material can provide means to increase the total protein yield and ultimately contribute to increased value creation of poultry by-products.

Sterile base florets in Triticum

1955 ◽  
Vol 3 (2) ◽  
pp. 149 ◽  
Author(s):  
C Barnard
Keyword(s):  
Triticum Aestivum ◽  
Distal Part ◽  
Triticum Aestivum L ◽  
The Other ◽  
Evolutionary Significance ◽  
Complete Suppression ◽  
Minimal Effect ◽  
The Third ◽  
High Degree

The morphology of the florets in three base-sterile speltoid mutants of Triticum aestivum L. is described. In two of the three mutants the basal floret only is affected. In one of these (St1) There is a high degree of sterility in the basal floret of all spikkelets except those on the distal part of the inflorescence; in the other (St1A) the basal floret of the basal and the distal spikelets is nearly always fertile, the highest degree of sterility being developed in the spikelets towards the middle of the ear. In the third mutant (St2) two florets are usually concerned. The basal floret of all spikelets except the apical one is practically always sterile. The second floret in the distal spikelets is mostly fertile, but in the lower spikelets it too is sterile and there is a gradient in fertility form distal to basal spikelets. The minimal effect of the sterility factor is the abortion or complete suppression of the anterior Stamen. This is accompanied by fusion and increased growth of the lodicule rudiments; all other floral parts develop normally. Greater incidence of the sterility results in the suppression of the lateral stamens with increased development of the lodioular structure and reduced growth of the palea. Fusion of the reduced palea and lodicular structure is usually followed by the abortion of the gynaeceum. In its extreme expression the sterility factor suppresses entirely the initiation of the flower primordium. Failure of florets in higher positions on the spikelets to form grain is due to immaturity and is different from basal sterility. When the basal florets are sterile, florets in higher positions than usual set grain. The mechanism by which the St genes operate and the evolutionary significance of basal sterility is discussed.

FORMATION OF CYCLIC O-2′-HYDROXYETHYLIDENE ACETALS FROM POLYALCOHOLS OF 4-O-LINKED POLYSACCHARIDES

1965 ◽  
Vol 43 (11) ◽  
pp. 2978-2984 ◽  
Author(s):  
P. A. J. Gorin ◽  
J. F. T. Spencer
Keyword(s):  
Acid Hydrolysis ◽  
Sodium Periodate ◽  
Rhodotorula Glutinis ◽  
Membered Ring ◽  
The Other ◽  
Complete Oxidation ◽  
Partial Acid Hydrolysis ◽  
Ring Form ◽  
Hydrolysis Of ◽  
By Products

Partial acid hydrolysis of polyalcohols derived from some 1,4-O-linked polysaccharides gave cyclic O-2′-hydroxyethylidene derivatives as by-products in yields of 6–18%. Polysaccharides containing β-links such as Rhodotorula glutinis mannan and cellulose gave rise to 6-membered ring acetals with lesser amounts of the 5-membered ring form. On the other hand, two α-linked polyalcohols, obtained following partial and complete oxidation of starch with sodium periodate, were converted to 5-membered O-2′-hydroxyethylidene acetals.

Purification and characterization of cycloisomaltotetraose-forming glucanotransferases from Agreia sp. D1110 and Microbacterium trichothecenolyticum D2006

2021 ◽  
Vol 85 (3) ◽  
pp. 600-610
Author(s):  
Akihiro Fujita ◽  
Akira Kawashima ◽  
Yuuki Mitsukawa ◽  
Noriaki Kitagawa ◽  
Hikaru Watanabe ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Culture Supernatant ◽  
Coupling Reaction ◽  
The Other ◽  
Purification And Characterization ◽  
Other Hand ◽  
Sds Page ◽  
Ph Range ◽  
Hydrolysis Of

ABSTRACT Glucanotransferases that can synthesize cyclo-{→6)-α-d-Glcp-(1→6)-α-d-Glcp-(1→6)-α-d-Glcp-(1→6)-α-d-Glcp-(1→} (CI4) from dextran were purified to homogeneity from the culture supernatant of Agreia sp. D1110 and Microbacterium trichothecenolyticum D2006. The molecular mass of both enzymes was estimated to be 86 kDa by SDS-PAGE. The glucanotransferase, named CI4-forming enzyme, from Agreia sp. exhibited the highest activity at pH 6.0 and 40 °C. The enzyme was stable on the pH range of 4.6-9.9 and up to 40 °C. On the other hand, the enzyme from M. trichothecenolyticum exhibited the highest activity at pH 5.7 and 40 °C. The enzyme was stable on the pH range of 5.0-6.9 and up to 35 °C. Both enzymes catalyzed 4 reactions, namely, intramolecular α-1,6-transglycosylation (cyclization), intermolecular α-1,6-transglycosylation, hydrolysis of CI4, and coupling reaction. Furthermore, the CI4-forming enzyme produced CI4 from α-1,6-linked glucan synthesized from starch by 6-α-glucosyltransferase. These findings will enable the production of CI4 from starch.

A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

2015 ◽  
Vol 12 (1) ◽  
pp. 3910-3918 ◽  
Author(s):  
Dr Remon M Zaki ◽  
Prof Adel M. Kamal El-Dean ◽  
Dr Nermin A Marzouk ◽  
Prof Jehan A Micky ◽  
Mrs Rasha H Ahmed
Keyword(s):  
Biological Activity ◽  
Carbonyl Compounds ◽  
Mass Spectra ◽  
The Other ◽  
Pyridine Derivatives ◽  
Facile Synthesis ◽  
High Biological Activity ◽  
Basic Hydrolysis ◽  
Pyridine Carboxylate ◽  
Hydrolysis Of

 Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f  which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

Temporal variability of disinfection by-products concentration in urban public water system

2013 ◽  
Vol 14 (4) ◽  
pp. 393-398
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Temporal Variability ◽  
Water System ◽  
The Other ◽  
Major Constituent ◽  
System P ◽  
Public Water System ◽  
Drinking Water Samples ◽  
By Products

The occurrence of trihalomethanes (THMs) was studied in the drinking water samples from urban water supply network of Karachi city that served more than 18 million people. Drinking water samples were collected from 58 locations in summer (May-August) and winter (November-February) seasons. The major constituent of THMs detected was chloroform in winter (92.34%) and summer (93.07%), while the other THMs determined at lower concentrations. Summer and winter concentrations of total THMs at places exceed the levels regulated by UEPA (80 μg l-1) and WHO (100 μg l-1). GIS linked temporal variability in two seasons showed significantly higher median concentration (2.5%-23.06%) of THMs compared to winter.

The effect of the molecular mass of the organic matter in raw water on the formation of disinfection by-products

2001 ◽  
Vol 50 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Chen-Yu Chang ◽  
Yung-Hsu Hsieh ◽  
Yu-Min Lin ◽  
Po-Yu Hu ◽  
Chin-Chuan Liu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Molecular Mass ◽  
Raw Water ◽  
By Products

C-Terminal amino acid sequence of chicken pepsinogen and its homology with sequences of other acid proteases

1980 ◽  
Vol 45 (4) ◽  
pp. 1144-1154 ◽  
Author(s):  
Miroslav Baudyš ◽  
Helena Keilová ◽  
Vladimír Kostka
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
The Other ◽  
Terminal Sequence ◽  
Terminal Part ◽  
Terminal Amino Acid ◽  
Tryptic Peptides ◽  
Terminal Amino ◽  
High Degree ◽  
Terminal Amino Acid Sequence

To determine the primary structure of the C-terminal part of the molecule of chicken pepsinogen the tryptic, chymotryptic and thermolytic digest of the protein were investigated and peptides derived from this region were sought. These peptides permitted the following 21-residue C-terminal sequence to be determined: ...Ile-Arg-Glu-Tyr-Tyr-Val-Ile-Phe-Asp-Arg-Ala-Asn-Asn-Lys-Val-Gly-Leu-Ser-Pro-Leu-Ser.COOH. A comparison of this structure with the C-terminal sequential regions of the other acid proteases shows a high degree of homology between chicken pepsinogen and these proteases (e.g., the degree of homology with respect to hog pepsinogen and calf prochymosin is about 66%). Additional tryptic peptides, derived from the N-terminal part of the zymogen molecule whose amino acid sequence has been reported before, were also obtained in this study. This sequence was extended by two residues using an overlapping peptide. An ancillary result of this study was the isolation of tryptic peptides derived from other regions of the zymogen molecule.

scholarly journals Polyphenol Profiling of Chestnut Pericarp, Integument and Curing Water Extracts to Qualify These Food By-Products as a Source of Antioxidants

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2335
Author(s):  
Gabriella Pinto ◽  
Sabrina De Pascale ◽  
Maria Aponte ◽  
Andrea Scaloni ◽  
Francesco Addeo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Negative Impact ◽  
Tap Water ◽  
Time Of Flight ◽  
The Other ◽  
Curing Process ◽  
Flight Mass Spectrometry ◽  
Water Curing ◽  
The Impact ◽  
By Products

Plant polyphenols have beneficial antioxidant effects on human health; practices aimed at preserving their content in foods and/or reusing food by-products are encouraged. The impact of the traditional practice of the water curing procedure of chestnuts, which prevents insect/mould damage during storage, was studied to assess the release of polyphenols from the fruit. Metabolites extracted from pericarp and integument tissues or released in the medium from the water curing process were analyzed by matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and electrospray-quadrupole-time of flight-mass spectrometry (ESI-qTOF-MS). This identified: (i) condensed and hydrolyzable tannins made of (epi)catechin (procyanidins) and acid ellagic units in pericarp tissues; (ii) polyphenols made of gallocatechin and catechin units condensed with gallate (prodelphinidins) in integument counterparts; (iii) metabolites resembling those reported above in the wastewater from the chestnut curing process. Comparative experiments were also performed on aqueous media recovered from fruits treated with processes involving: (i) tap water; (ii) tap water containing an antifungal Lb. pentosus strain; (iii) wastewater from a previous curing treatment. These analyses indicated that the former treatment determines a 6–7-fold higher release of polyphenols in the curing water with respect to the other ones. This event has a negative impact on the luster of treated fruits but qualifies the corresponding wastes as a source of antioxidants. Such a phenomenon does not occur in wastewater from the other curing processes, where the release of polyphenols was reduced, thus preserving the chestnut’s appearance. Polyphenol profiling measurements demonstrated that bacterial presence in water hampered the release of pericarp metabolites. This study provides a rationale to traditional processing practices on fruit appearance and qualifies the corresponding wastes as a source of bioactive compounds for other nutraceutical applications.

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