scholarly journals Anaerobic crystallization for protein crystallography

2014 ◽  
Vol 70 (a1) ◽  
pp. C1157-C1157
Author(s):  
Miki Senda ◽  
Toshiya Senda
Keyword(s):  
Protein Crystallization ◽  
Protein Crystallography ◽  
Crystal Formation ◽  
Anaerobic Conditions ◽  
Oxidized Proteins ◽  
Electron Transfer Proteins ◽  
Crystallization Conditions ◽  
Observation Method ◽  
Aerobic And Anaerobic ◽  
Anaerobic Chamber

Crystallization has been a bottleneck in protein crystallography. Major problems in protein crystallization are 1) to find crystallization conditions effectively at the initial crystallization screening and 2) to improve the reproducibility of protein crystallization. To overcome these problems, we have proposed some techniques such as the immediate observation method (1). Recently, we realized that films and precipitates of oxidized proteins hampered the crystal formation, leading to poor reproducibility of the crystallization. To avoid oxidation of proteins, we examined anaerobic crystallization in an anaerobic chamber. The anaerobic chamber (Anaerobic `HARD', Hirasawa) was designed to carry out controlled anaerobic experiments for electron-transfer proteins. We have so far established typical procedures for the anaerobic crystallization (2). On the basis of our earlier experiences, the anaerobic crystallization was tested for various proteins. We found obvious differences between aerobic and anaerobic crystallization in some cases; some proteins could crystallize only under anaerobic conditions. Furthermore, the anaerobic crystallization improved reproducibility of crystallization as expected. We will report some examples of the anaerobic crystallization.

Oxygen concentration affects frequency and range of transconjugants for the incompatibility (Inc) P-1 and P-7 plasmids pBP136 and pCAR1

2020 ◽  
Vol 85 (4) ◽  
pp. 1005-1015
Author(s):  
Kentaro Ochi ◽  
Maho Tokuda ◽  
Kosuke Yanagiya ◽  
Chiho Suzuki-Minakuchi ◽  
Hideaki Nojiri ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Anaerobic Condition ◽  
Environmental Samples ◽  
Aerobic Condition ◽  
Recipient Strain ◽  
Donor Strain ◽  
Anaerobic Conditions ◽  
Filter Mating ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

ABSTRACT The frequency of transconjugants were compared for the incompatibility (Inc) P-1 and P-7 plasmids pBP136 and pCAR1 under aerobic and anaerobic conditions. Filter mating assays were performed with one donor strain and one recipient strain using different donors of Pseudomonas and recipient strains, including Pseudomonas, Pantoea, and Buttiauxella. Under anaerobic condition, frequencies of transconjugants for both plasmids were 101-103-fold lower than those under aerobic condition regardless of whether aerobically or anaerobically grown donors and recipients were used. To compare the transconjugant ranges under aerobic and anaerobic conditions, conjugation was performed between the donor of pBP136 and recipient bacteria extracted from environmental samples. Several transconjugants were uniquely obtained from each aerobic or anaerobic condition. Our findings indicate that a plasmid can differently spread among bacteria depending on the oxygen concentrations of the environment.

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: VII. FERMENTATION OF WHEAT BY AEROBACILLUS POLYMYXA UNDER AEROBIC AND ANAEROBIC CONDITIONS

1946 ◽  
Vol 24f (1) ◽  
pp. 1-11 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Carbon Dioxide ◽  
Anaerobic Fermentation ◽  
Anaerobic Conditions ◽  
Mechanical Agitation ◽  
Fermentation Time ◽  
Aerobic Conditions ◽  
Ethanol Formation ◽  
Time Required ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Aeration by mechanical agitation of 15% wheat mash fermented by Aerobacillus polymyxa inhibited the formation of 2,3-butanediol and particularly of ethanol. Aeration of similar mashes by passage of finely dispersed air or oxygen at the rate of 333 ml. per minute per litre of mash increased the rate of formation and yield of 2,3-butanediol but inhibited ethanol formation. However, the over-all time required for the completion of fermentation was not shortened from the usual 72 to 96 hr. required for unaerated mashes. There was no evidence of a shift from fermentative to oxidative dissimilation. Under aerobic conditions, the final butanediol–ethanol ratio was approximately 3:1. Anaerobic conditions, as produced by the passage of nitrogen or hydrogen through the mash, increased the rate of formation of both butanediol and ethanol and shortened the fermentation time to about 48 hr. Under these conditions, the butanediol–ethanol ratio was reduced to about 1.3:1.0. Carbon dioxide gave a butanediol–ethanol ratio resembling that of anaerobic fermentation but did not reduce fermentation time.

scholarly journals Ionic Liquids as Protein Crystallization Additives

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1166
Author(s):  
Crissy L. Tarver ◽  
Qunying Yuan ◽  
Marc L. Pusey
Keyword(s):  
Ionic Liquids ◽  
Pathogenic Bacteria ◽  
Alkyl Chain ◽  
Protein Crystallization ◽  
Dihydrogen Phosphate ◽  
Base Metals ◽  
Butyl Group ◽  
Crystallization Conditions

Among its attributes, the mythical philosopher’s stone is supposedly capable of turning base metals to gold or silver. In an analogous fashion, we are finding that protein crystallization optimization using ionic liquids (ILs) often results in the conversion of base protein precipitate to crystals. Recombinant inorganic pyrophosphatases (8 of the 11 proteins) from pathogenic bacteria as well as several other proteins were tested for optimization by 23 ILs, plus a dH2O control, at IL concentrations of 0.1, 0.2, and 0.4 M. The ILs were used as additives, and all proteins were crystallized in the presence of at least one IL. For 9 of the 11 proteins, precipitation conditions were converted to crystals with at least one IL. The ILs could be ranked in order of effectiveness, and it was found that ~83% of the precipitation-derived crystallization conditions could be obtained with a suite of just eight ILs, with the top two ILs accounting for ~50% of the hits. Structural trends were found in the effectiveness of the ILs, with shorter-alkyl-chain ILs being more effective. The two top ILs, accounting for ~50% of the unique crystallization results, were choline dihydrogen phosphate and 1-butyl-3-methylimidazolium tetrafluoroborate. Curiously, however, a butyl group was present on the cation of four of the top eight ILs.

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