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911.
Firefly luciferase and fatty acyl-CoA synthetase are members of the acyl-CoA synthetase super family, which consists of a large N-terminal domain and a small C-terminal domain. Previously we found that firefly luciferase has fatty acyl-CoA synthetic activity, and also identified that the homolog of firefly luciferase in Drosophila melanogaster (CG6178) is a fatty acyl-CoA synthetase and is not a luciferase. In this study, we constructed chimeric proteins by exchanging the domain between Photinus pyralis luciferase (PpLase) and Drosophila CG6178, and determined luminescence and fatty acyl-CoA synthetic activities. A chimeric protein with the N-terminal domain of PpLase and the C-terminal domain of CG6178 (Pp/Dm) had luminescence activity, showing approximately 4% of the activity of wild-type luciferase. The Pp/Dm protein also had fatty acyl-CoA synthetic activity and the substrate specificity was similar to PpLase. In contrast, a chimeric protein with the N-terminal domain of CG6178 and the C-terminal of PpLase (Dm/Pp) had only fatty acyl-CoA synthetase activity, and the substrate specificity was similar to CG6178. These results suggest that the N-terminal domain of firefly luciferase is essential for substrate recognition, and that the C-terminal domain is indispensable but not specialized for the luminescence reaction. 相似文献
912.
Watanabe H Nishimoto T Kubota M Chaen H Fukuda S 《Bioscience, biotechnology, and biochemistry》2006,70(11):2690-2702
The gene for a novel glucanotransferase, isocyclomaltooligosaccharide glucanotransferase (IgtY), involved in the synthesis of a cyclomaltopentaose cyclized by an alpha-1,6-linkage [ICG5; cyclo-{-->6)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->}] from starch, was cloned from the genome of B. circulans AM7. The IgtY gene, designated igtY, consisted of 2,985 bp encoding a signal peptide of 35 amino acids and a mature protein of 960 amino acids with a calculated molecular mass of 102,071 Da. The deduced amino-acid sequence showed similarities to 6-alpha-maltosyltransferase, alpha-amylase, and cyclomaltodextrin glucanotransferase. The four conserved regions common in the alpha-amylase family enzymes were also found in this enzyme, indicating that this enzyme should be assigned to this family. The DNA sequence of 8,325-bp analyzed in this study contained two open reading frames (ORFs) downstream of igtY. The first ORF, designated igtZ, formed a gene cluster, igtYZ. The amino-acid sequence deduced from igtZ exhibited no similarity to any proteins with known or unknown functions. IgtZ was expressed in Escherichia coli, and the enzyme was purified. The enzyme acted on maltooligosaccharides that have a degree of polymerization (DP) of 4 or more, amylose, and soluble starch to produce glucose and maltooligosaccharides up to DP5 by a hydrolysis reaction. The enzyme (IgtZ), which has a novel amino-acid sequence, should be assigned to alpha-amylase. It is notable that both IgtY and IgtZ have a tandem sequence similar to a carbohydrate-binding module belonging to a family 25. These two enzymes jointly acted on raw starch, and efficiently generated ICG5. 相似文献
913.
Wada Y Kobayashi T Takahashi M Nakanishi H Mori S Nishizawa NK 《Bioscience, biotechnology, and biochemistry》2006,70(6):1408-1415
Nicotianamine (NA), a metal chelator, is ubiquitous in higher plants. In humans, NA inhibits angiotensin I-converting enzyme (ACE), and consequently reduces high blood pressure. Nicotianamine is synthesized from the trimerization of S-adenosylmethionine (SAM) by NA synthase (NAS). Here, we aimed to produce large amounts of NA fermentatively by introducing the Arabidopsis AtNAS2 gene into Saccharomyces cerevisiae strain SCY4. This strain can accumulate up to 100 times the usual amount of SAM, and this is considered desirable for overproduction of NA. Nicotianamine was produced in the engineered yeast, and the NA level increased with incubation time until the stationary phase. The maximum concentration of intracellular NA obtained was 766+/-33 microg/g wet weight. Successful production of NA in S. cerevisiae should pave the way for industrial production of this novel antihypertensive substrate. 相似文献
914.
Cochliophilin A (5-hydroxy-6,7-methylenedioxyflavone, 1), known as a host-specific attractant towards the zoospores of Aphanomyces cochlioides, a cause of root rot and damping-off diseases of Chenopodiaceae, was found in the Amaranthaceae plant, Celosia cristata, that is susceptible to the pathogen. The content of 1 in Celosia seedlings was quantified as 1.4 microg/g fresh weight. A new isoflavone, cristatein (5-hydroxy-6-hydroxymethyl-7,2'-dimethoxyisoflavone, 2), and five known flavonoids were also identified. 相似文献
915.
916.
Ono B Kubota M Kimiduka H Kawaminami H Ueto T Yokosawa S Iseda M Yamamoto Y Murakami Y Yokota S 《Bioscience, biotechnology, and biochemistry》2006,70(12):2813-2823
In the course of studying [PSI(+)], a yeast prion, we found inadvertently that Escherichia coli strain BL21 overproducing a fusion protein, in which the prion-domain of Sup35 was connected to the C terminus of glutathione S-transferase, grew normally to the stationary phase and rapidly decreased in colony-forming ability thereafter. Evidence indicated that protein polymers consisting mainly of the fusion protein GST-Sup35NM (about 70% of the mass) and its N-terminal fragments were formed in extract prepared from the cells producing GST-Sup35NM. It was further found that cells of strain BL21 accumulated the protein polymers during prolonged cultivation. Based on these results, we contend that the initially observed defect in colony forming ability is the direct or indirect consequence of intracellular formation and accumulation of the protein polymers. 相似文献
917.
Changes in the 4-hydroxy-2-hexenal (HHE) and malonaldehyde (MA) contents were investigated in the meat of the yellowtail Seriola quinqueradiate containing 0, 0.3, 0.6, and 0.9 M NaCl stored at 0 degrees C for 7 days. After 7 days of storage, the HHE content was significantly lower and the MA content significantly higher in the meat containing NaCl than in the control without NaCl. 相似文献
918.
Murashima K Shimonaka A Nishimura T Baba Y Koga J Kubota H Kono T 《Bioscience, biotechnology, and biochemistry》2006,70(9):2205-2212
EGL3 and RCE1 are glycoside hydrolase family 45 endoglucanases isolated from Humicola grisea and Rhizopus oryzae respectively. The amino acid sequences of the two endoglucanases are homologous; on the other hand, the optimum temperature of EGL3 is higher than that of RCE1. In this study, four chimeric endoglucanases, named ER1, ER2, ER3 and ER4, in which one of four sequential amino acid regions of the EGL3 catalytic domain (CAD) was replaced by the corresponding RCE1 amino acids, were constructed to explore the region responsible for the EGL3 temperature profile. Then their temperature profiles were compared with that of the recombinant EGL3. Replacement of the N-terminal region of EGL3 with that of RCE1 caused the EGL3 temperature profile to shift to a lower temperature. These results suggest that the N-terminal amino acids of the EGL3 are responsible for the EGL3 temperature profile. 相似文献
919.
Mizoguchi M Kitano S Takahashi W Sugawara F Tanaka O 《Bioscience, biotechnology, and biochemistry》2006,70(11):2751-2753
We have developed a simple and efficient method for protoplast isolation from Pleurotus cornucopiae. Protoplasts were isolated from aerial mycelia cultured on potato dextrose agar medium without time-consuming propagation in liquid culture. Protoplast yield was significantly increased by means of a decompressing pretreatment of mycelia in enzyme solution and a subsequent enzyme reaction with vibrational mixing. The isolated protoplasts regenerated mycelia and these mycelia formed fruit-bodies without any morphological abnormalities. 相似文献
920.
Shimonaka A Murashima K Koga J Baba Y Nishimura T Kubota H Kono T 《Bioscience, biotechnology, and biochemistry》2006,70(10):2460-2466
In the detergent industry, fungal endoglucanases are used to release microfibrils from the surfaces of dyed cellulosic fabrics to enhance color brightness. Family 45 endoglucanase (glycoside hydrolase family 45, GH45) EGL3 from Humicola grisea is more resistant to anionic surfactants and oxidizing agents than family 45 endoglucanase RCE1 from Rhizopus oryzae, while in the present study, a catalytic domain of RCE1 had higher defibrillation activity on dyed cotton fabrics than did that of EGL3. To identify the amino acid regions involved in these properties, we compared the characteristics of RCE1, EGL3, and three chimeric endoglucanases, in which each of the three regions of the catalytic domain of EGL3 was replaced by the corresponding region of the catalytic domain of RCE1. Amino acids in the N-terminal region were involved in resistance to anionic surfactants and oxidizing agents. Furthermore, amino acids in the region adjacent to the N-terminal region were involved in releasing microfibrils and in binding to dyed cotton fabrics, indicating that the binding of the amino acids in this region might be important in the release of microfibrils from dyed cotton fabrics. 相似文献