Bioconversion of ginsenosides Rb₁, Rb₂, Rc and Rd by novel β-glucosidase hydrolyzing outer 3-O glycoside from Sphingomonas sp. 2F2: Cloning, expression, and enzyme characterization

Wang, L.,Liu, Q.M.,Sung, B.H.,An, D.S.,Lee, H.G.,Kim, S.G.,Kim, S.C.,Lee, S.T.,Im, W.T. Elsevier Science Publishers 2011 Journal of biotechnology Vol.156 No.2

A new β-glucosidase gene (bglSp) was cloned from the ginsenoside converting Sphingomonas sp. strain 2F2 isolated from the ginseng cultivating filed. The bglSp consisted of 1344bp (447 amino acid residues) with a predicted molecular mass of 49,399Da. A BLAST search using the bglSp sequence revealed significant homology to that of glycoside hydrolase superfamily 1. This enzyme was overexpressed in Escherichia coli BL21 (DE3) using a pET21-MBP (TEV) vector system. Overexpressed recombinant enzymes which could convert the ginsenosides Rb<SUB>1</SUB>, Rb<SUB>2</SUB>, Rc and Rd to the more pharmacological active rare ginsenosides gypenoside XVII, ginsenoside C-O, ginsenoside C-Mc<SUB>1</SUB> and ginsenoside F<SUB>2</SUB>, respectively, were purified by two steps with Amylose-affinity and DEAE-Cellulose chromatography and characterized. The kinetic parameters for β-glucosidase showed the apparent K<SUB>m</SUB> and V<SUB>max</SUB> values of 2.9+/-0.3mM and 515.4+/-38.3μmolmin<SUP>-1</SUP>mg of protein<SUP>-1</SUP> against p-nitrophenyl-β-d-glucopyranoside. The enzyme could hydrolyze the outer C3 glucose moieties of ginsenosides Rb<SUB>1</SUB>, Rb<SUB>2</SUB>, Rc and Rd into the rare ginsenosides Gyp XVII, C-O, C-Mc<SUB>1</SUB> and F<SUB>2</SUB> quickly at optimal conditions of pH 5.0 and 37<SUP>o</SUP>C. A little ginsenoside F<SUB>2</SUB> production from ginsenosides Gyp XVII, C-O, and C-Mc<SUB>1</SUB> was observed for the lengthy enzyme reaction caused by the side ability of the enzyme.

Nitrate Reduction and Pigment Formation of Chinese-Style Sausage Mixes Caused by Micrococcaceae

Guo, H.L.,Chen, M.T.,Liu, D.C. Asian Australasian Association of Animal Productio 2000 Animal Bioscience Vol.13 No.8

This study investigated the nitrate reduction ability of Micrococcaceae on pigment formation in Chinese- style sausage. One hundred ppm sodium nitrite and 150 ppm sodium nitrate was added asepticly to ground pork which was then inoculated with $10^7CFU/g$ of either Micrococcus varians, Staphylococcus carnosus or Staphylococcus xylosus. All samples were cured at $20{^{\circ}C}$ or $30{^{\circ}C}$ for 3 days and then color, residue nitrite, nitrosyl pigment and residue nitrate were determined. The results indicated that samples inoculated with S. xylosus had higher a- and b- values due to nitrate reduction and pigment production after 3 days curing and these values were higher at the higher curing temperature. The nitrosyl pigment of the samples with S. xylosus had highest values after 3 days curing at both $20{^{\circ}C}$ and $30{^{\circ}C}$. However, sample inoculated with S. carnosus and S. xylosus had lower nitrate contents than the sample inoculated with M. varians. At $30{^{\circ}C}$ as well as S. carnosus and M. varians had a stronger decreasing in nitrate concentration during curing at $20{^{\circ}C}$. Moreover, samples inoculated with S. xylosus and S. carnosus had a higher residual nitrite content during curing at $20{^{\circ}C}$ or $30{^{\circ}C}$. In conclusion, two Staphylococci strains tested were most optimum starter cultures for improving pigment formation during Chinese-style sausage curing.

Fabricating Ultrathin Plate-Like WC Grains in WC–8Co Hardmetals by Increasing Discharge Intensity During Plasma-Assisted Ball Milling

M. Q. Zeng,J. L. Tu,M. Zhu,W. Wang,J. W. Liu,Z. C. Lu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.9

The effects of plasma discharge intensity on the microstructure evolution of ball-milled tungsten (W)–carbon (C)–cobalt (Co)mixtures and the formation mechanism of ultrathin plate-like tungsten carbide (WC) grains prepared by ball milling with andwithout plasma discharge were investigated. It was found that increasing the plasma discharge intensity during ball millingobviously promoted the formation of a thin flake-like W phase because of the electroplasticity effect and simultaneouslylowered the carburization temperature between W and C. A combination of high hardness and transverse rupture strength of92.9 HRA and 3659 MPa, respectively, was obtained for the WC–8Co alloy fabricated by plasma milling at a gas pressure of5 × 103 Pa with a dielectric barrier discharge layer thickness of 3 mm. These properties were mainly attributed to the markedlylowered activation energy of the WC phase and generation of highly oriented ultrathin plate-like WC grains by plasma milling. The combination of the flake-like structure of the plasma-milled W aggregate and high specific interfacial area and shortdiffusion distance of W/C were readily inherited by the ultrathin plate-like WC grains in the sintered WC–Co hardmetals.

Fine mapping and identification of candidate genes for the sy-2 locus in a temperature-sensitive chili pepper (Capsicum chinense)

Liu, L.,Venkatesh, J.,Jo, Y. D.,Koeda, S.,Hosokawa, M.,Kang, J. H.,Goritschnig, S.,Kang, B. C. Springer Science + Business Media 2016 Theoretical and applied genetics Vol.129 No.8

<P>The sy - 2 temperature-sensitive gene from Capsicum chinense was fine mapped to a 138.8-kb region at the distal portion of pepper chromosome 1. Based on expression analyses, two putative F-box genes were identified as sy - 2 candidate genes. Seychelles-2 ('sy-2') is a temperature-sensitive natural mutant of Capsicum chinense, which exhibits an abnormal leaf phenotype when grown at temperatures below 24 A degrees C. We previously showed that the sy-2 phenotype is controlled by a single recessive gene, sy-2, located on pepper chromosome 1. In this study, a high-resolution genetic and physical map for the sy-2 locus was constructed using two individual F-2 mapping populations derived from a cross between C. chinense mutant 'sy-2' and wild-type 'No. 3341'. The sy-2 gene was fine mapped to a 138.8-kb region between markers SNP 5-5 and SNP 3-8 at the distal portion of chromosome 1, based on comparative genomic analysis and genomic information from pepper. The sy-2 target region was predicted to contain 27 genes. Expression analysis of these predicted genes showed a differential expression pattern for ORF10 and ORF20 between mutant and wild-type plants; with both having significantly lower expression in 'sy-2' than in wild-type plants. In addition, the coding sequences of both ORF10 and ORF20 contained single nucleotide polymorphisms (SNPs) causing amino acid changes, which may have important functional consequences. ORF10 and ORF20 are predicted to encode F-box proteins, which are components of the SCF complex. Based on the differential expression pattern and the presence of nonsynonymous SNPs, we suggest that these two putative F-box genes are most likely responsible for the temperature-sensitive phenotypes in pepper. Further investigation of these genes may enable a better understanding of the molecular mechanisms of low temperature sensitivity in plants.</P>

Polymorphisms in the Promoter Region of the Chinese Bovine PPARGC1A Gene

Li, M.J.,Liu, M.,Liu, D.,Lan, X.Y.,Lei, C.Z.,Yang, D.Y.,Chen, H. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.4

The peroxisome proliferator-activated receptor gamma coactivator-1 alpha protein, encoded by the PPARGC1A gene, plays an important role in energy homeostasis. The genetic variations within the PPARGC1A gene promoter region were scanned in 808 Chinese native bovines belonging to three cattle breeds and yaks. A total of 6 SNPs and one 4 bp insertion variation in the promoter region of the bovine PPARGC1A gene were identified: SNP -259 T>A, -301_-298insCTTT, -915 A>G, -1175 T>G, -1590 C>T, -1665 C>T and -1690 G>A, which are in the binding sites of some important transcription factors: sex-determining region Y (SRY), myeloid-specific zinc finger-1 (MZF-1) and octamer factor 1(Oct-1). It is expected that these polymorphisms may regulate PPARGC1A gene transcription and might have consequences at a regulatory level.

EFFECTS OF ALTITUDE ON COMBUSTION CHARACTERISTIC DURING COLD START OF HEAVY-DUTY DIESEL ENGINE

Z. C. KAN,D. M. LOU,Z. Z. CAO,Z. Y. HU,S. LIU,Z. H. YANG 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.2

Altitude has a significant effect on combustion of heavy-duty diesel engines, especially during cold start. An experimental study on a heavy-duty diesel engine operating at different altitudes was conducted. Tests were based on a direct injection (DI) turbocharged diesel engine with intake and exhaust pressure controlled by the plateau simulation test system to stimulate altitude conditions including 0 m, 1000 m, 2000 m, 3000 m and 4000 m. Results indicated that the compression and expansion resistance moment reduced and the speed increased during the cranking period. The peak pressure of several cycles was increased during the start-up period; however, the expansion pressure dropped more and the indicated mean effective pressure (IMEP) reduced as the altitude rose. While at an altitude of over 2000 m, the peak pressure fluctuated obviously during the start-up period. The higher the altitude was, the more the fluctuation amplitude and cycle number increased and combustion instability enhanced, which resulted the start-up period time increasing at high altitude. When the altitude rose, the cycle-to-cycle variation of the peak pressure and speed fluctuation increased during the idle, the ignition and CA50 were delayed and the combustion duration was shortened. The effect of altitude on combustion characteristics of the diesel engine was more significant during the start-up period than during its idle period.

Association between Melatonin Receptor 1A Gene and Expression of Reproductive Seasonality in Sheep

Chu, M.X.,Cheng, D.X.,Liu, W.Z.,Fang, L.,Ye, S.C. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.8

To determine whether a link exists between reproductive seasonality and the structure of the melatonin receptor 1A (MTNR1A) gene, the latter was studied in nonseasonal estrous breeds (Small Tail Han and Hu ewes) and seasonal estrous breeds (Dorset, Suffolk and German Mutton Merino ewes). A large fragment of the exon 2 of the MTNR1A gene was amplified and a uniform fragment of 824 bp was obtained in 239 ewes of five breeds. The 824 bp PCR product was digested with restriction endonucleases Mnl I and Rsa I, and checked for the presence of restriction sites. The presence (allele M) or absence (allele m) of an Mnl I site at base position 605 led to three genotypes MM (236 bp/236 bp), Mm (236 bp/303 bp) and mm (303 bp/303 bp) in five sheep breeds. The presence (allele R) or absence (allele r) of a Rsa I site at base position 604 led to three genotypes RR (267 bp/267 bp), Rr (267 bp/290 bp) and rr (290 bp/290 bp) in five sheep breeds. Frequencies of MM and RR genotypes were obviously higher, and frequencies of mm and rr genotypes were obviously lower in nonseasonal estrous sheep breeds than in seasonal estrous sheep breeds. Sequencing revealed four mutations (G453T, G612A, G706A, C891T) in mm genotype compared to MM genotype and one mutation (C606T) in rr genotype compared to RR genotype. For polymorphic Mnl I and Rsa I cleavage sites, the differences of genotype distributions were very highly significant (p<0.01) between Small Tail Han ewes and seasonal estrous sheep breeds. In each group, no significant difference (p>0.05) was detected. These results preliminarily showed an association between MM, RR genotypes and nonseasonal estrus in ewes and an association between mm, rr genotypes and seasonal estrus in ewes.

Characterization of trnk-matk Gene in Potato Plastid

Jung, M 한국식물조직배양학회 1998 식물생명공학회지 Vol.25 No.6

Novel anti-apoptotic mechanism of A20 through targeting ASK1 to suppress TNF-induced JNK activation

Won, M,Park, K A,Byun, H S,Sohn, K-C,Kim, Y-R,Jeon, J,Hong, J H,Park, J,Seok, J H,Kim, J M,Yoon, W-H,Jang, I-S,Shen, H M,Liu, Z G,Hur, G M Macmillan Publishers Limited 2010 CELL DEATH AND DIFFERENTIATION Vol.17 No.12

The zinc-finger protein A20 has crucial physiological functions as a dual inhibitor of nuclear factor-κB (NF-κB) activation and apoptosis in tumor necrosis factor (TNF) receptor 1 signaling pathway. Although the molecular basis for the anti-NF-κB function of A20 has been well elucidated, the anti-apoptotic function of A20 is largely unknown. Here, we report a novel mechanism underlying the anti-apoptotic function of A20: A20 blocks TNF-induced apoptosis through suppression of c-jun N-terminal kinase (JNK) by targeting apoptosis signal-regulating kinase1 (ASK1). First, the ectopic expression of A20 drastically inhibits TNF-induced JNK activation and apoptosis in multiple cell types including those deficient of NF-κB activation. Unexpectedly, the blunting effect of A20 on TNF-induced JNK activation is not mediated by affecting the TNFR1 signaling complex formation. Instead, A20 interacts with ASK1, an important MAPKK kinase in the JNK signaling cascade. More importantly, overexpression of wild-type A20, but not of mutant A20 (ZnF4; C624A, C627A), promotes degradation of the ASK1 through the ubiquitin-proteasome system. Taken together, the results from this study reveal a novel anti-apoptotic mechanism of A20 in TNF signaling pathway: A20 binds to ASK1 and mediates ASK1 degradation, leading to suppression of JNK activation and eventually blockage of apoptosis.

Regulation of heme oxygenase-1 gene by peptidoglycan involves the interaction of Elk-1 and C/EBP α to increase expression

Hung, C.-C.,Liu, X.,Kwon, M.-Y.,Kang, Y.-H.,Chung, S.W.,Perrella, M.A. AMERICAN PHYSIOLOGICAL SOCIETY 2010 American Journal of Physiology: Lung cellular and Vol.298 No.6