• Journal of Microbiology and Biotechnology
• /
• v.17 no.6
• /
• pp.1010-1017
• /
• 2007

Two alternative pathways for methionine biosynthesis are known in Corynebacterium glutamicum: one involving transsulfuration (mediated by metB and metC) and the other involving direct sulfhydrylation (mediated by metY). In this study, MetB (cystathionine ${\gamma}-synthase$) and MetY (O-acetylhomoserine sulfhydrylase) from C. glutamicum were purified to homogeneity and the biochemical parameters were compared to assess the functional and evolutionary importance of each pathway. The molecular masses of the native MetB and MetY proteins were measured to be approximately 170 and 280 kDa, respectively, showing that MetB was a homotetramer of 40-kDa subunits and MetY was a homohexamer of 45-kDa subunits. The $K_m$ values for the O-acetylhomoserine catalysis effected by MetB and MetY were 3.9 and 6.4 mM, and the maximum catalysis rates were $7.4\;(k_{cat}=21\;S^{-1})\;and\;6.0\;(k_{cat}=28\;S^{-1})\;{\mu}mol\;mg^{-1}\;min^{-1}$, respectively. This suggests that both MetB and MetY can be comparably active in vivo. Nevertheless, the $K_m$ value for sulfide ions by MetY was 8.6mM, which was too high, considering the physiological condition. Moreover, MetB was active at a broad range of temperatures $(30\;and\;65^{\circ}C)$ and pH (6.5 and 10.0), as compared with MetY, which was active in a range from 30 to $45^{\circ}C$ and at pH values from 7.0 to 8.5. In addition, MetY was inhibited by methionine, but MetB was not. These biochemical data may provide insight on the role of the parallel pathways of methionine biosynthesis in C. glutamicum with regard to cell physiology and evolution.

• Journal of Chest Surgery
• /
• v.50 no.3
• /
• pp.153-162
• /
• 2017

Background: The mesenchymal-epithelial transition factor (MET) receptor can be overexpressed in solid tumors, including small cell lung cancer (SCLC). However, the molecular mechanism regulating MET stability and turnover in SCLC remains undefined. One potential mechanism of MET regulation involves the C-terminus of Hsp70-interacting protein (CHIP), which targets heat shock protein 90-interacting proteins for ubiquitination and proteasomal degradation. In the present study, we investigated the functional effects of CHIP expression on MET regulation and the control of SCLC cell apoptosis and invasion. Methods: To evaluate the expression of CHIP and c-Met, which is a protein that in humans is encoded by the MET gene (the MET proto-oncogene), we examined the expression pattern of c-Met and CHIP in SCLC cell lines by western blotting. To investigate whether CHIP overexpression reduced cell proliferation and invasive activity in SCLC cell lines, we transfected cells with CHIP and performed a cell viability assay and cellular apoptosis assays. Results: We found an inverse relationship between the expression of CHIP and MET in SCLC cell lines (n=5). CHIP destabilized the endogenous MET receptor in SCLC cell lines, indicating an essential role for CHIP in the regulation of MET degradation. In addition, CHIP inhibited MET-dependent pathways, and invasion, cell growth, and apoptosis were reduced by CHIP overexpression in SCLC cell lines. Conclusion: C HIP is capable of regulating SCLC cell apoptosis and invasion by inhibiting MET-mediated cytoskeletal and cell survival pathways in NCI-H69 cells. CHIP suppresses MET-dependent signaling, and regulates MET-mediated SCLC motility.

• Journal of Nutrition and Health
• /
• v.47 no.3
• /
• pp.176-185
• /
• 2014

Purpose: The purpose of this study was to investigate the relationship between dietary flavonoids intake and metabolic syndrome (MetS) in Korean women with polycystic ovary syndrome (PCOS). Methods: A total of 223 subjects (mean age; $27.3{\pm}4.2$ yrs, range; 17-38 yrs) were divided into the MetS group (n = 27) and non-MetS group (n = 196). Dietary intake data were assessed by 24-hour recall method for two non-consecutive days and the average of the two days was used to estimate the usual dietary intake. Dietary habits were assessed using the Mini Dietary Assessment (MDA) score. We analyzed the intakes of six flavonoid classes (anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, and iso-flavones) using a flavonoids database. Results: After adjustment for age, total energy intake, alcohol consumption, smoking, regular exercise, and oral contraceptive use, dietary flavonols intake was significantly lower in the MetS group ($5.1{\pm}2.4$ mg/d) than in the non-MetS group ($8.9{\pm}2.8$ mg/d) (p = 0.0472). Intakes of other flavonoids except for flavonols did not differ between the two groups. In MDA scores, significant differences were observed only for that related to daily consumption of fruit or fruit juice (p = 0.0180). A significant inverse relationship was observed between flavonols intake and the risk of MetS (4th vs. 1st quartile, OR = 0.11, 95% CI = 0.02-0.62, p for trend = 0.0131). Conclusion: These results suggest that higher intake of flavonols may be beneficial for MetS in PCOS women.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.12
• /
• pp.1804-1808
• /
• 2003

A layer experiment was conducted to determine the effects of supplementary methionine chelates (Cu, Zn and Mn), individual or in combination, on laying performance, eggshell quality, gizzard erosion, and IgG level of serum for 8 weeks. Five hundred 96-wk-old force molted ISA Brown layers were assigned to five dietary treatments. Basal diet was formulated to meet or exceed the nutrients requirements listed in NRC (1994). Five experimental diets were control, Zn-methionine chelate (Zn-Met) supplemented, Cumethionine chelate (Cu-Met) supplemented, Zn-Mn-methionine chelate (Zn-Mn-Met) supplemented and Zn-Mn-Cu-Met supplemented diet. Each treated diet was supplemented with respective mineral(s) at the level of 100 ppm in the form of methionine chelate. Egg production was increased by Cu-Met supplementation but decreased by Zn-Met supplementation. Egg weight was significantly (p<0.05) lower in Cu-Met treatment than those of the control and Zn-Met treatment. Specific gravity of eggs and eggshell strength were highest and soft egg production was lowest in Cu-Met treatment. Gizzard erosion index was significantly increased by supplementation of Cu-Met, Zn-Mn-Met or Zn-Mn-Cu-Met. Zinc content in liver significantly increased by Zn-Met, but not by Zn-Mn-Cu-Met treatment. In conclusion, 100 ppm Cu in Cu-Met chelate improved laying performance and eggshell quality but also increased gizzard erosion index. Supplementation of Zn-Met or its combination with other mineral chelates had no beneficial effects on laying performance and eggshell quality.

• Korean Journal of Head & Neck Oncology
• /
• v.21 no.1
• /
• pp.15-20
• /
• 2005

Objectives: The hepatocyte growth factor(HGF)/c-Met pathway may play various roles in the carcinogenesis of various organs. Although HGF/c-Met signalling pathway has been shown to demonstrate various cellular responses including mitogenic, proliferative, morphogenic and angiogenic activities, the study on their expression related to clinicopathological parameters in thyroid tumor is relatively rare. So we want to find out the clinical significance of the c-Met in thyroid tumor. Materials and Methods: We assess the mRNA and protein expression of the c-Met genes by means of RT-PCR method and the immunohistochemical stain in 100 cases of thyroid tumors(50 papillary carcinomas, 10 follicular carcinomas, 20 follicular adenomas, 20 nodular hyperplasia). Results: By RT-PCR, c-Met mRNA was detected in 43(86%) in papillary carcinoma, 4(40%) in follicular carcinoma, 4(20%) in follicular adenoma and 2(10%) in nodular hyperplasia cases. By immunohistochemistry, c-Met protein expression was detected in 44(88%), 2(20%), 3(15%) and 1(5%). Expression of the c-Met mRNA and protein expression was significantly highly recognized in papillary carcinoma. The c-Met protein overexpression was significantly correlated with the grade of the differentiation. Conclusion: These results suggest that c-Met expression may be associated with thyroid papillary cancer progression. The differential expression of c-Met protein and mRNA suggests that these molecules may be a reliable diagnostic marker in thyroid papillary cancer.

• Journal of Gastric Cancer
• /
• v.16 no.3
• /
• pp.141-151
• /
• 2016

Purpose: The aim of the present study was to elucidate the clinicopathological significance and diagnostic accuracy of immunohistochemistry (IHC) for determining the mesenchymal epidermal transition (c-MET) expression in patients with gastric cancer (GC). Materials and Methods: The present meta-analysis investigated the correlation between c-MET expression as determined by IHC and the clinicopathological parameters in 8,395 GC patients from 37 studies that satisfied the eligibility criteria. In addition, a concordance analysis was performed between c-MET expression as determined by IHC and c-MET amplification, and the diagnostic test accuracy was reviewed. Results: The estimated rate of c-MET overexpression was 0.403 (95% confidence interval [CI], 0.327~0.484) and it was significantly correlated with male patients, poor differentiation, lymph node metastasis, higher TNM stage, and human epidermal growth factor receptor 2 (HER2) positivity in IHC analysis. There was a significant correlation between c-MET expression and worse overall survival rate (hazard ratio, 1.588; 95% CI, 1.266~1.992). The concordance rates between c-MET expression and c-MET amplification were 0.967 (95% CI, 0.916~0.987) and 0.270 (95% CI, 0.173~0.395) for cases with non-overexpressed and overexpressed c-MET, respectively. In the diagnostic test accuracy review, the pooled sensitivity and specificity were 0.56 (95% CI, 0.50~0.63) and 0.79 (95% CI, 0.77~0.81), respectively. Conclusions: The c-MET overexpression as determined by IHC was significantly correlated with aggressive tumor behavior and positive IHC status for HER2 in patients with GC. In addition, the c-MET expression status could be useful in the screening of c-MET amplification in patients with GC.

• Journal of Korean Medicine Rehabilitation
• /
• v.24 no.1
• /
• pp.93-100
• /
• 2014

Objectives To evaluate the clinical utility of MET performed on sternocleidomastoid muscle of acute nuchal pain patients, we measured a change of meridian electromyography. Methods We compared electrical activity before and after MET performed on sternocleidomastoid muscle of acute nuchal pain patients in same group (n=20) in isometric exercise state during five seconds. We analyzed amplitudes and areas of electrical activity and asymmetry index (AI). Results 1. After MET performed on sternocleidomastoid muscle of acute nuchal pain patients, maximum voluntary isomeric contraction (MVIC) was significantly increased more than before MET performed (p<0.005). 2. Comparing with before MET performed on sternocleidomastoid muscle of acute nuchal pain patients, muscle fatigue after MET performed on sternocleidomastoid muscle of acute nuchal pain patients decreased but there was no significant difference. 3. Comparing with before MET performed on sternocleidomastoid muscle of acute nuchal pain patients, asymmetry index (AI) after MET performed on sternocleidomastoid muscle of acute nuchal pain patients decreased but there was no significant difference. Conclusions According to above results, after performing MET on sternocleidomastoid muscle of acute nuchal pain patients, maximum voluntary isomeric contraction (MVIC) increased significantly, so it is certain that performing MET on sternocleidomastoid muscle has a clinical effect.

• Journal of Korean Medicine Rehabilitation
• /
• v.23 no.1
• /
• pp.15-23
• /
• 2013

Objectives : To evaluate the clinical utility of MET in elector spinae muscle on low back pain patients. Methods : We compared electrical activity between a before MET and a after MET in elector spinae muscle on low back pain patients in same group(n=30) in dynamic flexion-reextension state during five seconds. We analyzed amplitudes and areas of electrical activity and asymmetry index(AI). Results : 1. After MET in elector spinae muscle on low back pain patients were significantly decreased in Visual Analogue Scale(VAS) than before MET in elector spinae muscle on low back pain patients(p<0.05). 2. After MET in elector spinae muscle on low back pain patients were lower electrical activity than before MET in elector spinae muscle on low back pain patients but it is not a pointless observation(p<0.05). 3. AI of the after MET in elector spinae muscle on low back pain patients significantly decreased compared with before MET in elector spinae muscle on low back pain patients(p<0.05). Conclusions : According to above results, there is clinical effect MET on low back pain patients.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.2
• /
• pp.319-326
• /
• 1997

This study was conducted to investigate the effects of methionine(Met) and selenium(Se) levels on alcohol metabolic enzyme system in rats. Sprague-Dawley male rats were fed on diets containing one of the three levels of Met(0, 3, 9g/kg diet) with or without Se(0.45mg/kg diet). Alcohol was administrated with 25%(v/v) ethanol orally at the same time once a day in alcohol group and isocaloric sucrose was administrated to the control group. The rats were sacrificed after 5 and 10 week of feeding periods. Alcohol dehydrogenase(ADH) and microsomal ethanol oxidizing system(MEOS) activities of hepatic tissuedom were increased more in alcohol treated groups than control group. Increment of activities preinated in simultaneous deficiency of dietary Met and Se(LMet-Se+EtOH) group. Aldehyde dehydrogenase (AIDH) activity was decreased more in alcohol treated groups than control group and significantly decreased in Met and Se supplemented(NMet+Se+EtOH) group. Hepatic cytochrome P-450 content and xanthine oxidase(XO) activity were significantly increased in alcohol treated groups Compared to control group and predominated in Met deficiency(LMet) group and excessive Met administration (HMet) group. Superoxide dismutase(SOD), catalase, glutathione S-transferase(GST) activities tended to increase by alcohol administration, the degree of increase predominated in 10 week. The activity of glutathione peroxidase(GSH-Px) was decreased in alcohol groups and tended to increase in proportion to the level of dietary Met.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.1
• /
• pp.55-61
• /
• 1984

A Korean local maize line, MET, which has multi-ears and tillers has been proved as a potential source for silage production. However, no fundamental genetic nature for the line has been investigated. Therefore, this study was done to find genetic information on the multi-earing and -tillering habits of MET line. MET line and a hybrid. (Mo 17 ${\times}$ B68), with monoculm and single ear per plant were used for production of F$_1$(F$\_$1-12/ and F$\_$1-21/), F$\_$2-12/, F$\_$2-21/, BC$\_$1-12/ and BC$\_$1-21/ generations. From the comparison of reciprocal crosses, it was found that the tillering and earing habits of the MET line are controlled by cytoplasmic factors. The tiller and ear numbers, and barren ears were all characters associated with the MET cytoplasm. The cytoplasmic effect of MET on tiller and ear numb en was not evident in F$_1$ generation, probably because of suppressing effect of heterosis on appearance of tillers or ears. Genetic parameters for the gene action for both tiller and ear number also indicated a lack of mono- or digenic-chromosomal gene effects. The heritability (broad) was very low for both characters. Therefore, it is strongly concluded that the tillering and earing characters of MET line are due to cytoplasmic reasons.