Mutation of Phe413 to Tyr in catalase KatE from Escherichia coli leads to side chain damage and main chain cleavage

2012 ◽  
Vol 525 (2) ◽  
pp. 207-214 ◽  
Author(s):  
Vikash Jha ◽  
Lynda J. Donald ◽  
Peter C. Loewen
Keyword(s):  
Escherichia Coli ◽  
Main Chain ◽  
Side Chain ◽  
Chain Cleavage

Photodegradation mechanism of phenyl isopropenyl ketone – methyl methacrylate copolymers in the solid phase and their performance as a deep UV resist

1995 ◽  
Vol 73 (11) ◽  
pp. 1841-1848 ◽  
Author(s):  
Kazuyuki Sugita ◽  
Tomohito Ishida ◽  
Masahito Kushida ◽  
Kieko Harada ◽  
Kyoichi Saito ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Main Chain ◽  
Solid Phase ◽  
Chain Scission ◽  
Quantum Yields ◽  
Side Chain ◽  
Type I ◽  
Side Chain Cleavage ◽  
Chain Cleavage ◽  
Norrish Type

Phenyl isopropenyl ketone (PIPK) copolymer films were irradiated with a low-pressure mercury lamp, and benzoyl side-chain cleavage and main-chain scission at various temperatures were followed by UV spectral changes and gel permeation chromatography, respectively. Quantum yields of both reactions and the ratio of the latter to the former reaction increased markedly above their glass transition temperatures. The main-chain scission continued to proceed by irradiation even after the side chain ceased to split. These experimental results suggest a new reaction mechanism of photosplitting of the methyl methacrylate ester side chain on the carbon adjacent to the C=C bond followed by β-scission, in addition to the known benzoyl side-chain cleavage followed by β-scission or C=C bond formation. The enhanced quantum yield for the main-chain scission of the PIPK copolymer at 130 °C realized sensitivity of 100 mJ/cm2 as a DUV resist, which was 1200 times as high as that of poly(methyl methacrylate) exposed at room temperature and developed under similar conditions. Keywords: Norrish type I cleavage, β-scission of main chain, temperature dependence, photosplitting of ester side chain, conjugated polymer radical.

The Anaerobic Side-Chain Cleavage of Bile Acids by Escherichia coli Isolated from Human Faeces

1977 ◽  
Vol 5 (6) ◽  
pp. 1758-1760 ◽  
Author(s):  
MICHAEL E. TENNESON ◽  
ROBERT W. OWEN ◽  
ARTHUR N. MASON
Keyword(s):  
Escherichia Coli ◽  
Bile Acids ◽  
Side Chain ◽  
Human Faeces ◽  
Side Chain Cleavage ◽  
Chain Cleavage

Errors and reproducibility in electron-density map interpretation

1999 ◽  
Vol 55 (7) ◽  
pp. 1309-1319 ◽  
Author(s):  
Sherry L. Mowbray ◽  
Charlotte Helgstrand ◽  
Jill A. Sigrell ◽  
Alexander D. Cameron ◽  
T. Alwyn Jones
Keyword(s):  
Escherichia Coli ◽  
Electron Density ◽  
Main Chain ◽  
Real Space ◽  
Side Chain ◽  
Map Interpretation ◽  
Quality Check ◽  
Density Map ◽  
Electron Density Map

Three investigators, with varying levels of experience, independently built and refined the structure of Escherichia coli ribokinase at 2.6 Å resolution. At the end of the refinement/rebuilding processes the models had essentially converged, although each had its own particular pattern of remaining errors. The subsequent refinement of the same structure at 1.8 Å resolution allowed an overall quality check of each of the lower resolution models, and an analysis of which graphics-based tools were generally most efficient in locating these errors. Criteria which are useful in the application of Ramachandran, main-chain and side-chain database and real-space fit analyses are presented.

scholarly journals Non-Specific GH30_7 Endo-β-1,4-xylanase from Talaromyces leycettanus

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4614
Author(s):  
Katarína Šuchová ◽  
Nikolaj Spodsberg ◽  
Kristian B. R. Mørkeberg Krogh ◽  
Peter Biely ◽  
Vladimír Puchart
Keyword(s):  
General Formula ◽  
Main Chain ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Side Chain ◽  
Biotechnological Applications ◽  
Xylose Residue ◽  
Great Tolerance ◽  
Chain Cleavage ◽  
Hydrolysis Of

This study describes the catalytic properties of a GH30_7 xylanase produced by the fungus Talaromyces leycettanus. The enzyme is an ando-β-1,4-xylanase, showing similar specific activity towards glucuronoxylan, arabinoxylan, and rhodymenan (linear β-1,3-β-1,4-xylan). The heteroxylans are hydrolyzed to a mixture of linear as well as branched β-1,4-xylooligosaccharides that are shorter than the products generated by GH10 and GH11 xylanases. In the rhodymenan hydrolyzate, the linear β-1,4-xylooligosaccharides are accompanied with a series of mixed linkage homologues. Initial hydrolysis of glucuronoxylan resembles the action of other GH30_7 and GH30_8 glucuronoxylanases, resulting in a series of aldouronic acids of a general formula MeGlcA2Xyln. Due to the significant non-specific endoxylanase activity of the enzyme, these acidic products are further attacked in the unbranched regions, finally yielding MeGlcA2Xyl2-3. The accommodation of a substituted xylosyl residue in the −2 subsite also applies in arabinoxylan depolymerization. Moreover, the xylose residue may be arabinosylated at both positions 2 and 3, without negatively affecting the main chain cleavage. The catalytic properties of the enzyme, particularly the great tolerance of the side-chain substituents, make the enzyme attractive for biotechnological applications. The enzyme is also another example of extraordinarily great catalytic diversity among eukaryotic GH30_7 xylanases.

Expression of functional bovine cholesterol side chain cleavage cytochrome P450 (P450scc) in Escherichia coli

1991 ◽  
Vol 290 (2) ◽  
pp. 376-380 ◽  
Author(s):  
Akira Wada ◽  
Porunelloor A. Mathew ◽  
Henry J. Barnes ◽  
Donita Sanders ◽  
Ronald W. Estabrook ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cytochrome P450 ◽  
Side Chain ◽  
Side Chain Cleavage ◽  
Chain Cleavage

P450 side-chain cleavage enzyme autoantibodies in canine Addison's disease

2013 ◽  
pp. 1-1
Author(s):  
Alisdair Boag ◽  
Kerry McLaughlin ◽  
Mike Christie ◽  
Peter Graham ◽  
Harriet Syme ◽  
...  
Keyword(s):  
Addison’S Disease ◽  
Side Chain ◽  
Addison's Disease ◽  
Side Chain Cleavage ◽  
Chain Cleavage ◽  
Cleavage Enzyme
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