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81.
Ha YM Park YJ Lee JY Park D Choi YJ Lee EK Kim JM Kim JA Park JY Lee HJ Moon HR Chung HY 《Biochimie》2012,94(2):533-540
Herein we describe the design, synthesis and biological activities of 2-(substituted phenyl)thiazolidine-4-carboxylic acid derivatives as novel tyrosinase inhibitors. The target compounds 2a–2j were designed and synthesized from the structural characteristics of N-phenylthiourea, tyrosinase inhibitor and tyrosine, and l-DOPA, the natural substrates of tyrosinase. Among them, (2R/S,4R)-2-(2,4-dimethoxyphenyl)thiazolidine-4-carboxylic acid (2g) caused the greatest inhibition 66.47% at 20 μM of l-DOPA oxidase activity of mushroom tyrosinase. Kinetic analysis of tyrosinase inhibition revealed that 2g is a competitive inhibitor. We predicted the tertiary structure of tyrosinase, and simulated the docking of mushroom tyrosinase with 2g. These results suggest that the binding affinity of 2g with tyrosinase is high. Also, 2g effectively inhibited tyrosinase activity and reduced melanin levels in B16 cells treated with α-MSH. These data strongly suggest that 2g can suppress the production of melanin via the inhibition of tyrosinase activity. 相似文献
82.
Shin HJ 《Applied microbiology and biotechnology》2012,93(5):1895-1904
In this study, recombinant bacterial biosensors were immobilized in an agarose matrix and used for the simple and disposable
field monitoring of phenolic compounds. In brief, Escherichia coli cells harboring the pLZCapR plasmid, which was previously designed to express the β-galactosidase reporter gene in the presence
of phenolic compounds, were immobilized in agarose gel with or without a substrate [chlorophenol red β-galactopyranoside (CPRG)]
and dispensed to the wells of a 96-well plate. Analytes were added to the wells, and color development was monitored either
directly from wells containing intact cells co-immobilized with CPRG (SYS I), or using cells that were lysed prior to the
addition of CPRG (SYS L). SYS L showed relatively higher intensities and faster color development than SYS I. However, both
systems developed a red color (representing hydrolysis of CPRG) in the presence of 10 μM to 10~100 mM phenol, with maximum
responses seen at 1~5 and 50 mM phenol for SYS I and SYS L, respectively. Other phenolic compounds (2-chlorophenol, 2-methylphenol,
3-methylphenol, 4-chlorophenol, 2-nitrophenol, resorcinol, catechol, and 2,5-dimethylphenol) were also detected by the systems,
with varied detection ranges and responses. The agarose-immobilized biosensors were stable for 28 days, retaining 39~69% of
their activities when stored at 4°C without nutrients or additives. The immobilized biosensors described herein do not require
the on-site addition of a substrate (in the case of SYS I), the pretreatment of samples, or the use of unwieldy instruments
for the on-site monitoring of phenolic compounds from environmental samples. 相似文献
83.
The unclassified marine gammaproteobacterium BDW918, which utilizes volatile fatty acids but not most common carbohydrates and amino acids, was isolated from Dokdo seawater in South Korea. Here we present a draft genome of the strain BDW918, which encodes many putative genes related to fatty acid metabolism and aromatic hydrocarbon degradation. 相似文献
84.
Park JY Park JH Jang W Hwang IK Kim IJ Kim HJ Cho KH Lee ST 《Journal of biochemistry》2012,151(3):291-298
Screening of matrix metalloproteinase (MMP)-14 substrates in human plasma using a proteomics approach previously identified apolipoprotein A-IV (apoA-IV) as a novel substrate for MMP-14. Here, we show that among the tested MMPs, purified apoA-IV is most susceptible to cleavage by MMP-7, and that apoA-IV in plasma can be cleaved more efficiently by MMP-7 than MMP-14. Purified recombinant apoA-IV (44-kDa) was cleaved by MMP-7 into several fragments of 41, 32, 29, 27, 24, 22 and 19 kDa. N-terminal sequencing of the fragments identified two internal cleavage sites for MMP-7 in the apoA-IV sequence, between Glu(185) and Leu(186), and between Glu(262) and Leu(263). The cleavage of lipid-bound apoA-IV by MMP-7 was less efficient than that of lipid-free apoA-IV. Further, MMP-7-mediated cleavage of apoA-IV resulted in a rapid loss of its intrinsic anti-oxidant activity. Based on the fact that apoA-IV plays important roles in lipid metabolism and possesses anti-oxidant activity, we suggest that cleavage of lipid-free apoA-IV by MMP-7 has pathological implications in the development of hyperlipidemia and atherosclerosis. 相似文献
85.
Kim DH Kim JM Lee EK Choi YJ Kim CH Choi JS Kim ND Yu BP Chung HY 《The Journal of nutritional biochemistry》2012,23(10):1277-1284
Baicalin is a flavonoid known to modify various redox-related biological activities. Included is its ability to suppress reactive species (RS) producing activity and modulate nuclear factor-κB through cellular redox regulation with enhanced thiol ability. FoxO regulates various genes that are known to be involved in cellular metabolism related to cell death and the oxidative stress response. One such case is the prevention of FoxO1 expression by activated insulin-induced phosphatidylinositol 3-kinase (PI3K)/Akt, which leads to increased oxidative stress and aging processes. In the present study, we attempted to elucidate the molecular modulation of antioxidant baicalin on the insulin-induced FoxO1 inactivation. We used HEK293T cultured cells and kidney tissue isolated from 24-month-old rats treated with baicalin at a dose of 10 or 20 mg/kg/day for 10 days. We found that baicalin enhanced catalase and suppressed RS production in cell system and in isolated kidney tissue in contrast to the nontreated aged rats. Results also showed activation of insulin signaling (PI3K/Akt), FoxO1 phosphorylation/acetylation and the down-regulation of catalase and manganese superoxide dismutase, both of which are FoxO1-targeting genes. Furthermore, baicalin-treated rats showed a decreased FoxO1 phosphorylation via PI3K/Akt cascade and FoxO1 acetylation by the cAMP-response element-binding protein binding protein (CBP). These results strongly suggest that treatment with baicalin influenced phosphorylation/acetylation of FoxO1 by up-regulating PI3K/Akt signaling through insulin in aged rats. Our results further reveal that baicalin regulated FoxO1 phosphorylation via PI3K/Akt by insulin and FoxO1 acetylation by the interaction of CBP and SIRT1, leading to changes in catalase gene expression during aging. 相似文献
86.
Park AR Cho AR Seo JA Min K Son H Lee J Choi GJ Kim JC Lee YW 《Fungal genetics and biology : FG & B》2012,49(7):511-520
Regulators of G protein signaling (RGS) proteins make up a highly diverse and multifunctional protein family that plays a critical role in controlling heterotrimeric G protein signaling. In this study, seven RGS genes (FgFlbA, FgFlbB, FgRgsA, FgRgsB, FgRgsB2, FgRgsC, and FgGprK) were functionally characterized in the plant pathogenic fungus, Gibberella zeae. Mutant phenotypes were observed for deletion mutants of FgRgsA and FgRgsB in vegetative growth, FgFlbB and FgRgsB in conidia morphology, FgFlbA in conidia production, FgFlbA, FgRgsB, and FgRgsC in sexual development, FgFlbA and FgRgsA in spore germination and mycotoxin production, and FgFlbA, FgRgsA, and FgRgsB in virulence. Furthermore, FgFlbA, FgRgsA, and FgRgsB acted pleiotropically, while FgFlbB and FgRgsC deletion mutants exhibited a specific defect in conidia morphology and sexual development, respectively. Amino acid substitutions in Gα subunits and overexpression of the FgFlbA gene revealed that deletion of FgFlbA and dominant active GzGPA2 mutant, gzgpa2(Q207L), had similar phenotypes in cell wall integrity, perithecia formation, mycotoxin production, and virulence, suggesting that FgFlbA may regulate asexual/sexual development, mycotoxin biosynthesis, and virulence through GzGPA2-dependent signaling in G. zeae. 相似文献
87.
88.
89.
Touw CM Smit GP de Vries M de Klerk JB Bosch AM Visser G Mulder MF Rubio-Gozalbo ME Elvers B Niezen-Koning KE Wanders RJ Waterham HR Reijngoud DJ Derks TG 《Orphanet journal of rare diseases》2012,7(1):30
ABSTRACT: BACKGROUND: Since the introduction of medium-chain acyl coenzyme A dehydrogenase (MCAD) deficiency in population newborn bloodspot screening (NBS) programs, subjects have been identified with variant ACADM (gene encoding MCAD enzyme) genotypes that have never been identified in clinically ascertained patients. It could be hypothesised that residual MCAD enzyme activity can contribute in risk stratification of subjects with variant ACADM genotypes. METHODS: We performed a retrospective cohort study of all patients identified upon population NBS for MCAD deficiency in the Netherlands between 2007-2010. Clinical, molecular, and enzymatic data were integrated. RESULTS: Eighty-four patients from 76 families were identified. Twenty-two percent of the subjects had a variant ACADM genotype. In patients with classical ACADM genotypes, residual MCAD enzyme activity was significantly lower (median 0%, range 0-8%) when compared to subjects with variant ACADM genotypes (range 0-63%; 4 cases with 0%, remainder 20-63%). Patients with (fatal) neonatal presentations before diagnosis displayed residual MCAD enzyme activities <1%. After diagnosis and initiation of treatment, residual MCAD enzyme activities <10% were associated with an increased risk of hypoglycaemia and carnitine supplementation. The prevalence of MCAD deficiency upon screening was 1/8,750 (95% CI 1/7,210-1/11,130). CONCLUSIONS: Determination of residual MCAD enzyme activity improves our understanding of variant ACADM genotypes and may contribute to risk stratification. Subjects with variant ACADM genotypes and residual MCAD enzyme activities <10% should be considered to have the same risks as patients with classical ACADM genotypes. Parental instructions and an emergency regimen will remain principles of the treatment in any type of MCAD deficiency, as the effect of intercurrent illness on residual MCAD enzyme activity remains uncertain. There are, however, arguments in favour of abandoning the general advice to avoid prolonged fasting in subjects with variant ACADM genotypes and 10% residual MCAD enzyme activity. 相似文献
90.
Yoon Kyung Jo Seung Cheol Kim In Ja Park So Jung Park Dong-Hoon Jin Seung-Woo Hong Dong-Hyung Cho Jin Cheon Kim 《PloS one》2012,7(12)