Correcting for the effect of ambient pressure fluctuations on measured output from a linear accelerator with a sealed monitor chamber.

Ambient pressure fluctuations deform the walls of a sealed monitor chamber in a linear accelerator (LINAC) and affect the output. This study retrospectively quantified the output variations accompanying ambient pressure fluctuations in a LINAC equipped with a sealed monitor chamber and introduced a novel approach of calculating the adjusted output free from the effect of ambient pressure fluctuations.The output data for the 6 MV and 10 MV X-rays measured between March 2014 and September 2015 were analysed.

[Efficient Commissioning of the Radiotherapy Treatment Planning System with the Golden Beam Data].

Commissioning of a linear accelerator (Linac) and treatment planning systems (RTPs) for clinical use is complex and time-consuming, typically 3-4 months in total. However, based on clinical needs and economics, hospitals desire early clinical starts for patients, and various studies have been conducted for shortening the preparation period. One of the methods to shorten the period is using golden beam data (GBD).

Gene cloning, recombinant expression, purification and characterization of l-methionine decarboxylase from Streptomyces sp. 590.

l-Methionine decarboxylase (MetDC) from Streptomyces sp. 590 depends on pyridoxal 5'-phosphate and catalyzes the non-oxidative decarboxylation of l-methionine to produce 3-methylthiopropylamine and carbon dioxide. MetDC gene (mdc) was determined to consist of 1,674 bp encoding 557 amino acids, and the amino acid sequence is similar to that of l-histidine decarboxylases and l-valine decarboxylases from Streptomyces sp.

Suppressive effect of poly-gamma-glutamate on SOS response of Salmonella typhimurium induced by chemical mutagens.

We studied the suppressive effect of poly-gamma-glutamate (PGA) on the SOS response of Salmonella typhimurium induced by several direct [furylframide, AF-2; N-methyl-N'-nitro-N-nitrosoguanidine, MNNG; and 4-nitroquinoline 1-oxide, 4NQO] and indirect [3-amino-1-methyl-5H-pyrido-(4,3-b) indole, Trp-P-2; 2-amino-3-methylimidazo (4,5-f) quinoline, IQ; and 2-amino-3,8-dimethylimidazo (4,5-f) quinoxaline, MeIQx] mutagens. PGA preparations with average molecular masses of 50, 2000, 4000, 6000, and 8000 kDa from Bacillus subtilis (chungkookjang) were used. When we used PGA Na salt with a molecular mass of 4000 kDa, the suppression rate increased with increasing PGA concentration; 3% PGA showed 80-90% suppression irrespective of the type of chemical mutagen.

Crystallization and preliminary X-ray diffraction studies of tetrameric malate dehydrogenase from the novel Antarctic psychrophile Flavobacterium frigidimaris KUC-1.

Flavobacterium frigidimaris KUC-1 is a novel psychrotolerant bacterium isolated from Antarctic seawater. Malate dehydrogenase (MDH) is an essential metabolic enzyme in the citric acid cycle and has been cloned, overexpressed and purified from F. frigidimaris KUC-1.

A cold-active and thermostable alcohol dehydrogenase of a psychrotorelant from Antarctic seawater, Flavobacterium frigidimaris KUC-1.

An NAD(+)-dependent alcohol dehydrogenase of a psychrotorelant from Antarctic seawater, Flavobacterium frigidimaris KUC-1 was purified to homogeneity with an overall yield of about 20% and characterized enzymologically. The enzyme has an apparent molecular weight of 160k and consists of four identical subunits with a molecular weight of 40k. The pI value of the enzyme and its optimum pH for the oxidation reaction were determined to be 6.

Simple improvement in freeze-tolerance of bakers' yeast with poly-gamma-glutamate.

We examined the effect of poly-gamma-glutamate (PGA) on the freeze-tolerance of four types of commercial bakers' yeast (freeze-tolerant, osmotic-tolerant, low-temperature-sensitive, and ordinary bakers' yeasts). The survival ratio of ordinary bakers' yeast cells frozen at -30 degrees C for 3 d in a medium (0.5% yeast extract, 0.

Alanine racemase of alfalfa seedlings (Medicago sativa L.): first evidence for the presence of an amino acid racemase in plants.

We demonstrated several kinds of D-amino acids in plant seedlings, and moreover alanine racemase (E.C.5.

Natural and edible biopolymer poly-gamma-glutamic acid: synthesis, production, and applications.

Poly-gamma-glutamic acid (gamma-PGA) is a very promising biodegradable polymer that is produced by Bacillus subtilis. Gamma-PGA is water-soluble, anionic, biodegradable, and edible. This paper reviews the production of a strain of gamma-PGA and recent developments with respect to applications in terms of Ca absorption, moisturizing properties, gamma-PGA conjugation, super absorbent polymer, and so on.

Flavobacterium frigidimaris sp. nov., isolated from Antarctic seawater.

We described the polyphasic characterization of the psychrotolerant isolated from Antarctic seawater. The strain was closely related to Flavobacterium hydatis, F. pectinovorum, and F.

Enzymatic synthesis of high-molecular-mass poly-gamma-glutamate and regulation of its stereochemistry.

For the first time, we succeeded in synthesizing in vitro poly-gamma-glutamate (PGA) with high molecular masses (>1,000 kDa) by the use of enzyme-associated cell membranes from Bacillus subtilis subsp. chungkookjang. The activity for PGA synthesis, however, was readily lost in the presence of critical concentrations of detergents tested in micelles.

Assay method for antitumor L-methionine gamma-lyase: comprehensive kinetic analysis of the complex reaction with L-methionine.

L-Methionine gamma-lyase (EC 4.4.1.

Novel psychrophilic and thermolabile L-threonine dehydrogenase from psychrophilic Cytophaga sp. strain KUC-1.

A psychrophilic bacterium, Cytophaga sp. strain KUC-1, that abundantly produces a NAD(+)-dependent L-threonine dehydrogenase was isolated from Antarctic seawater, and the enzyme was purified. The molecular weight of the enzyme was estimated to be 139,000, and that of the subunit was determined to be 35,000.

Differences in effects on DNA gyrase activity between two glutamate racemases of Bacillus subtilis, the poly-gamma-glutamate synthesis-linking Glr enzyme and the YrpC (MurI) isozyme.

Bacillus subtilis possesses two isogenes encoding glutamate racemases, the poly-gamma-glutamate synthesis-linking Glr enzyme and the YrpC isozyme, and produces abundant amounts of the Glr enzyme. The YrpC isozyme, but not the Glr enzyme, was found to influence the activity of DNA gyrase, as did the MurI-type glutamate racemase of Escherichia coli, which is involved in peptidoglycan synthesis during cell division.

Thermostable aspartase from a marine psychrophile, Cytophaga sp. KUC-1: molecular characterization and primary structure.

We found that a psychrophilic bacterium isolated from Antarctic seawater, Cytophaga sp. KUC-1, abundantly produces aspartase [EC4.3.

D-arginase of Arthrobacter sp. KUJ 8602: characterization and its identity with Zn(2+)-guanidinobutyrase.

D-Arginase activity was found in the cells of an isolate, Arthrobacter sp. KUJ 8602, grown in the L-arginine medium, and the enzyme was purified and characterized. Its molecular weight was estimated to be about 232,000 by gel filtration, and that of the subunit was approximately 40,000 by SDS-PAGE, suggesting that the enzyme is a homohexamer.

Subunit interaction of monomeric alanine racemases from four Shigella species in catalytic reaction.

Bacterial alanine racemases are classified into two types of subunit structure (monomer and homodimer). To clarify the catalytic unit of monomeric alanine racemases, we examined the apparent molecular mass of the monomeric alanine racemases from Shigella dysenteriae, Shigella boydii, Shigella flexneri, and Shigella sonnei by gel filtration in the presence of the substrate and inhibitor. The enzymes were eluted on gel filtration as a monomer of about 39,000 Da at low protein concentration and in the absence of L-alanine and D-cycloserine.

Thermostable aldehyde dehydrogenase from psychrophile, Cytophaga sp. KUC-1: enzymological characteristics and functional properties.

We found the occurrence of NAD(P)(+)-dependent aldehyde dehydrogenase (EC1.2.1.

Glutamate racemase is an endogenous DNA gyrase inhibitor.

Almost all bacteria possess glutamate racemase to synthesize d-glutamate as an essential component of peptidoglycans in the cell walls. The enforced production of glutamate racemase, however, resulted in suppression of cell proliferation. In the Escherichia coli JM109/pGR3 clone, the overproducer of glutamate racemase, the copy number (i.

Crystallization and preliminary X-ray analysis of substrate complexes of leucine dehydrogenase from Thermoactinomyces intermedius.

Leucine dehydrogenase is an octameric enzyme which belongs to the superfamily of amino-acid dehydrogenases and catalyses the reversible oxidative deamination of leucine to 2-ketoisocaproate, with the corresponding reduction of the cofactor NAD(+). Catalysis by this enzyme is thought to involve a large-scale motion of the enzyme's two domains between an 'open' and 'closed' form, with the latter representing a conformation of the enzyme in which the partners involved in the hydride-transfer reaction are appropriately positioned for catalysis. Whilst a structure for the open form of the enzyme has been determined, the nature of the closed form has yet to be observed.