Toyama Prefectural University | Date: 2017-02-22
The objective of the present invention is to provide a (R)-hydroxynitrile lyase which is more stable than a hydroxynitrile lyase derived from a plant, a gene which encodes the hydroxynitrile lyase and by which heterologous expression is possible, and a method for producing the hydroxynitrile lyase. The (R)-hydroxynitrile lyase according to the present invention is characterized in having the specific amino acid sequence such as the amino acid sequence of SEQ ID NO: 3.
Nakamura M.,Toyama Prefectural University
2016 IEEE 5th Global Conference on Consumer Electronics, GCCE 2016 | Year: 2016
In the OTS/CafeOBJ method, systems are described in CafeOBJ algebraic specification language, and verified by using equational reasoning. A proof score is a script of verification. We have proposed a method which generate skeleton Java codes and test cases from specifications and proof scores, however, test cases generated from the method are not complete, that is, there are blanks to be filled to be executed. In this study, we propose a way to instantiate the generated test cases by using CafeOBJ rewrite specifications and search command to obtain a test case generation method which generate executable test cases. © 2016 IEEE.
Koyama Y.,Toyama Prefectural University |
Gudeangadi P.G.,Toyama Prefectural University
Chemical Communications | Year: 2017
We developed a one-pot synthetic technique for alternating peptides. Central to this technique is a new, catalyst-free polymerization based on Ugi's 4CC reaction. The treatment of imines with the ambident molecules bearing both an isocyanide and a carboxylic acid afforded alternating peptides. © The Royal Society of Chemistry.
Toda H.,Toyama Prefectural University |
Itoh N.,Toyama Prefectural University
Journal of Bioscience and Bioengineering | Year: 2012
Styrene metabolism genes were isolated from styrene-assimilating bacteria Rhodococcus sp. ST-5 and ST-10. Strain ST-5 had a gene cluster containing four open reading frames which encoded styrene degradation enzymes. The genes showed high similarity to styABCD of Pseudomonas sp. Y2. On the other hand, strain ST-10 had only two genes which encoded styrene monooxygenase and flavin oxidoreductase (styAB). Escherichia coli transformants possessing the sty genes of strains ST-5 and ST-10 produced (S)-styrene oxide from styrene, indicating that these genes function as styrene degradation enzymes. Metabolite analysis by resting-cell reaction with gas chromatography-mass spectrometry revealed that strain ST-5 converts styrene to phenylacetaldehyde via styrene oxide by styrene oxide isomerase (styC) reaction. On the other hand, strain ST-10 lacked this enzyme, and thus accumulated styrene oxide as an intermediate. HPLC analysis showed that styrene oxide was spontaneously isomerized to phenylacetaldehyde by chemical reaction. The produced phenylacetaldehyde was converted to phenylacetic acid (PAA) in strain ST-10 as well as in strain ST-5. Furthermore, phenylacetic acid was converted to phenylacetyl-CoA by the catalysis of phenylacetate-CoA ligase in strains ST-5 and ST-10. This study proposes possible styrene metabolism pathways in Rhodococcus sp. strains ST-5 and ST-10. © 2011 The Society for Biotechnology, Japan.
Dadashipour M.,Toyama Prefectural University |
Asano Y.,Toyama Prefectural University
ACS Catalysis | Year: 2011
Hydroxynitrile lyases are valuable enzymes for asymmetric synthesis of cyanohydrins. These hydroxyl and nitrile-containing compounds are being used in production of very useful pharmaceuticals, agrochemicals, and other biologically active compounds using chemical or chemoenzymatic follow-up reactions in industry. Although a huge amount of information exists on the reaction parameters of these enzymes, including stability to pH and organic solvents, yield, reaction time, and valuable data on the enantiopurity of their products, cyanohydrins, there is a lack of update on the biochemistry, discovery, and engineering of the HNLs. Therefore, in the Introduction, we will have a look into these enzymes, cyanohydrins, and aldoxime-nitrile pathways. A brief view of functional groups and several examples of cyanohydrin-based chemicals and pharmaceuticals will also be described. Then we will present characteristics of many S- and R-selective HNLs with comparative tables for several enzymatic properties under biochemistry section. The methods of screening and discovery of these enzymes both from nature and a library of mutants will be described as well as their potential in the synthesis of chemicals. Cloning and expression of new HNLs will also be described under the discovery section. A pool of successful applications of protein engineering methods and the subsequent improvement in the properties of mutant HNLs will be reviewed in detail afterward. © 2011 American Chemical Society.
Takagi N.,Toyama Prefectural University
Conference Proceedings - IEEE International Conference on Systems, Man and Cybernetics | Year: 2010
A computer-aided system for transformation of mathematical figures into tactile graphics is useful for visually impaired students when they learn mathematics and science. To develop such a system, research on mathematical figure recoguition techniques is needed. It is natural to assume that (1) mathematical figures include characters and formulas to explain lines or curves that are graphical expressions of functions or equations, and (2) graphs are sometimes drawn using broken lines. Under these assumptions, this paper discusses a method of separating a mathematical figure into character components and graph components, and a classification method of broken lines. ©2010 IEEE.
Ikushiro S.,Toyama Prefectural University
Drug Metabolism Reviews | Year: 2010
UDP-glucuronosyltransferases (UGT) comprise a large gene superfamily that can be classified, based on the degree of amino-acid similarity between isoforms, into several gene families. Among these gene families, the UDP-glucuronosyltransferase family 1 (UGT1) gene is a unique gene complex organized to generate enzymes that share a common carboxyl terminal portion and are unique in the variable amino terminal region. Each variable exon I is preceded by a regulatory 5'-region and, in response to a specific signal, transcription processing splices mRNA from each unique exon 1 to the four common exons ( 2, 3, 4, and 5) to provide a template for synthesis of the individual isoforms. A novel clue to elucidate the gene structure of mammalian UGT1 was cDNA cloning of rat UGT1A6 from the hyperbilirubinemic Gunn rat by Professor Takashi Iyanagi Ph.D. The elucidation of the structure of the rat UGT1 gene complex has led to a greater understanding of the genetic basis of Crigler-Najjar and Gilbert's syndromes. Now, examination of the UGT1 gene structure in hyperbilirubinemic patients has revealed more than 100 different genetic defects in Crigler-Najjar syndromes and one genetic alternation that accounts for the majority of Gilbert's syndrome cases. This review of a chapter in UGT history will focus on the extensive research of Iyanagi and coworkers with the rat UGT1 gene complex and advancing to the study of the human gene. © 2010 Informa UK Ltd.
Fuhshuku K.-I.,Toyama Prefectural University |
Asano Y.,Toyama Prefectural University
Journal of Biotechnology | Year: 2011
Both enantiomers of β-nitro alcohols are versatile chiral building blocks. However, their synthesis using enzymes as catalysts has received little attention, with the exception of (S)-β-nitro alcohols produced in a reaction catalyzed by an S-selective hydroxynitrile lyase (HNL) from Hevea brasiliensis (HbHNL). An R-selective HNL containing an α/β-hydrolase fold from the noncyanogenic plant Arabidopsis thaliana (AtHNL) accepts nitromethane (MeNO 2) as a donor in a reaction with aromatic aldehydes to yield (R)-β-nitro alcohols (Henry reaction; nitro aldol reaction). This reaction proceeded in an aqueous-organic biphasic system. The organic solvent giving the highest enantioselectivity was n-butyl acetate (AcOBu) with an optimum aqueous phase content of 50% (v/v). This is the first example of the R-HNL-catalyzed synthesis of (R)-β-nitro alcohols. © 2011 Elsevier B.V.
Hirahara T.,Toyama Prefectural University
Proceedings of Meetings on Acoustics | Year: 2013
The effect of listener's voluntary movement on the horizontal sound localization was investigated using a binaural recording/reproduction system with TeleHead, a steerable dummy head. Stimuli were static binaural signals recorded with a still dummy-head in head-still condition, dynamic binaural signals recorded with a dummy-head that followed precise or modified listener's head rotation, dynamic binaural signals produced by steering-wheel rotation with listener's hands in head-still condition, and dynamic binaural signals produced by an experimenter in head-still condition. For the static binaural signals, some were localized within the head and the front-back errors often occurred. For the dynamic binaural signals, none of them was localized within the head, and the front-back confusions seldom occurred. Sound images of the dynamic binaural stimuli produced by head rotation were localized out-of head, while those produced by the steering-wheel rotation or by an experimenter were moving around the listener's head. Listeners could judge the orientation of each stimulus more correctly with dynamic binaural signals produced by listener's head or steering-wheel rotation than with static binaural signals and with dynamic binaural signals produced by an experimenter. Results suggest that the dynamic binaural signal associated with listener's voluntary movement plays a crucial role in sound localization. © 2013 Acoustical Society of America.
News Article | November 9, 2015
Stinky millipedes that swarm into houses at night in Japan may hold the key to speedy synthesis of important chiral molecules useful for making pharmaceuticals, agrochemicals, and other chemical products. A team of researchers led by Yasuhisa Asano at Toyama Prefectural University, in Japan, found that Chamberlinius hualienensis, a millipede originally from Taiwan that invaded Japan in the 1980s, produces an enzyme called hydroxynitrile lyase that is much faster at producing enantiometrically . . .