• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.1026-1032
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• 2006

The present experiment was conducted to assess the efficacy of liquid methionine hydroxy analogue-free acid (MHA-FA) in comparison to DL-methionine (DL-Met) in broilers. 567 day-old Avian chicks were divided into 7 treatments with 5 replicates of 16 birds each. During the 35d (7-42 d) experimental periods chicks were given two basal diets. From 7 to 21d of age, a starting basal diet containing 19.5% protein and 0.33% methionine was supplemented with two graded levels of DL-Met (0.070 and 0.160%) or four levels of MHA-FA (0.118, 0.143, 0.221 and 0.268%). From 22 to 42d of age DL-Met (0.050 and 0.080%) or MHA-FA (0.071, 0.074, 0.112 and 0.140%) were added to a finishing basal diet with 18.0% protein and 0.28% methionine. Chicks fed on supplemental DL-Met or MHA-FA had significantly higher (p<0.05) body weight gain and feed conversion ratio (FCR) than the control group from 7-21d of age. During the finishing phase (22-42 d), body weight and weight gain of chicks in DL-Met or MHA-FA treatments were similar to those in the control, but FCR was improved (p<0.05) with supplementation of DL-Met or MHA-FA. Breast yield was higher (p<0.05) on DL-Met or MHA-FA supplemented than un-supplemented diets. The thigh meat yields emanating from diets with DL-Met or MHA-FA were lower (p<0.05) than that in control. Abdominal fat was also higher in broilers fed the control diet than in DL-Met or MHA-FA supplemented treatments. Methionine requirement of broilers was calculated to be 0.44 and 0.35% and cystine requirement was 0.35 and 0.31% for the starting (7-21 d) and finishing phase (22-42 d), respectively. The efficacy of MHA-FA in comparison to DL-Met for weight gain was 64 and 85% and for FCR was 55 and 60% at 7-21 and 22-42 d of age, respectively, while it was 74, 72, 52 and 48% for breast yield, thigh meat production, body energy content and energy deposition ratio at 42 d of age, respectively. In conclusion, in practical diet formulation for broiler chicks the average bioavailability of MHA-FA relative to DL-Met could be considered as 60 and 73% for 7 to 21d and 22 to 42 d of age, respectively.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.301-304
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• 2005

S-Adenosyl-L-Methionine(SAM) has an important role for DNA methylation and cell signaling. SAM was synthesized from methionine and ATP by SAM synthetase and play an pivotal function in the primary and secondary metabolism of cells. Recent studies have revealed in the effect of SAM in case of morphological differentiation in both eukaryotes and prokaryotes. We isolated SAM gene from Saccharomyces cerevisiae and cloned it into expression vector for E. coli respectively. An 1.15 kb SAM-s gene fragment was isolated by Low-strigency PCR using ORF primer. By the analysed primary sequence deduced from DNA sequence, this gene included conserved domains similar with other well-known SAM synthetase. First of all, SAM synthetase gene cloned pGEM-T vector and subcloned into histidine tagging system to purify the expressed protein using metal chelating resin. Typical characteristic analysis of this enzyme is underway.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.97-105
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• 2006

In order to investigate the effect of inhibitors on L-threonine biosynthesis in Escherichia coli, we have constructed a metabolic network model of amino acid biosynthesis from L-aspartate to L-threonine by using available informations from literatures and databases. In the model, the effects of inhibitors on the biosynthesis of L-threonine was included as an appropriate mathematical form. For simulation study, we used initial values as L-aspartate 5 mM, ATP 5 mM, NADPH 2 mM, and observed the concentration changes of intermediate metabolites over concentration changes of respective inhibitors. As a result, we found that concentrations of intermediate metabolites were not significantly changed over concentration changes of L-lysine, L-methionine, and L-glutamate. But, there were considerable changes of intermediates over concentration changes of L-serine, L-cysteine, and L-threonine, which can be considered as essential effectors on L-threonine synthesis. Contrary, the synthesis of L-threonine seems to be not related to the amounts of L-aspartate, and inversely proportional to the accumulated amount of D,L-aspartic ${\beta}$-semialdehyde.

• Journal of Ginseng Research
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• v.33 no.4
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• pp.260-267
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• 2009

Recent studies have shown that Panax ginseng has a variety of beneficial effects on the cardiovascular system. Homocysteine (Hcy), which is derived from methionine, has been closely associated with the increased risk of cardiovascular diseases. In the present study, whether the in-vivo long-term co-administration of ginseng total saponins (GTS), active ingredients of Panax ginseng, with L-methionine (Met) inhibits methionine-induced hyperhomocysteine (HHcy) and H-Hcy-induced cardiovascular dysfunctions was investigated, and it was found that the plasma Hcy level, which was measured after 30 and 60 days, in the GTS+Met co-administration group was more significantly reduced than in the Metalone-treatment group. The left-ventricle (LV) wall thickness of the heart was likewise examined in each treatment group, and it was found that the co-administration of GTS with Met significantly reduced the Met-induced LV wall thickness. The results of the study indicate that the in-vivo long-term co-administration of GTS with Met not only inhibited H-Hcy induced by long-term Met-alone administration but also attenuated the H-Hcy-induced cardiovascular dysfunctions in rats.

• Proceedings of the Botanical Society of Korea Conference
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• 2002.04a
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• pp.73-82
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• 2002

The committing step in Met and S-adenosyl-L-methionine (SAM) synthesis is catalyzed by cystathionine ${\gamma}$ -synthase (CGS). Transgenic Arabidopsis thaliana overexpressing CGS under control of 35S promoter show increased soluble Met and its metabolite S-methylmethionine, but only at specific stages of development. CGS-overexpressing seedlings are resistant to ethionine. Similar results were obtained with transgenic potato plants overexpressing Arabidopsis CGS. Several of the transgenic lines show silencing of CGS resulting in deformed p]ants with a reduced capacity for reproductive growth similar as transgenic plants by antisense RNA (CGS[-]). Exogenous feeding of Met to the CGS[-] and CGS[+] silenced plants partially restores their growth. Similar morphological deformities are observed in plants cosuppressed for SAM synthetase, even though such plants accumulate 250 fold more soluble Met than wild type and they overexpress CGS. The results suggest that the abnormalities associated with CGS and SAM synthetase silencing are due in part to a reduced ability to produce SAM, and that SAM may be a regulator of CGS expression.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1025-1031
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• 2008

S-Adenosyl-L-methionine (SAM) exerts several beneficial effects on depression, chronic diseases, and cognitive impairments. Bifidobactrium bifidum BGN4 reportedly produces higher amounts of SAM than any other lactic acid bacterium used in yogurt. The aim of this study was to develop a SAM-reinforced probiotic yogurt using Bifidobacterium. The sensory aspects of the yogurt via response surface methodology (RSM) and the texture and SAM content of the yogurt were assessed. Based on the sensory assessments for sweetness, sourness, and thickness evaluated by 48 panelists, the optimized conditions for preparation of SAM-reinforced yogurt were 4.0-4.4%(w/w) sugar, 3.2-3.5%(w/w) skim milk, and a pH of 4.7-4.8. The SAM content of the developed yogurt was 0.05 nmol/mL. In conclusion, SAM-reinforced probiotic yogurt may provide a vehicle for the potential exploitation of the benefits of increased dietary SAM.

• Korean Journal of Plant Resources
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• v.10 no.3
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• pp.221-226
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• 1997

Improvement of seed protein quality might be an essential issus in soybean and would give more profit directly to both farmers and users. This study was carried out to investigate the effects of reduced-S form(s) on seed storage protein components in soybean during seed filling stages. The reduced-S forms during seed fill were sodium thiosulfate, sodium sulfite, sodium sulfide, thioaceteat, $\beta$-mercaptoethanol, thiourea, thiamine-HCI, L-cysteine, L-cystine, and L-methionine. Seed storage protein concentration did not appear to be affected by any reduced-S forms. However, glycinin and $\beta$-conglycinin concentration seemed to be changed greatly by L-methionine. This resulted in the increase in the 11S/7S ratio(3.58). Among the $\beta$-conglycinin, $\beta$-subunit was not accumulated at all. $\alpha$-subunit concentration appeared to be decreased and $\alpha'$-subunit concentration was not altered in comparison with sulfate control. Also, $\beta$-conglycine concentration, especially $\beta$-subunit concentration, tended to be decreased with L-cystine treatment, resulting in an increase in the 11S/7S ratio(1.83). The glycinin concentration tended to be increased at the expense of the decrease in the $\beta$-conglycinin concentration. Therefore, it is suggested that enhancing soybean protein quality would be achieved by improving metabolic pathways of S assimilation in soybean plants during seed filling period under sulfate-sufficient condition.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.1-7
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• 1998

A total of 120 pigs $(L\;{\times}\;LW\;{\times}\;D)$ averaged 14.16 kg of body weight were reared under six dietary treatments to evaluate the effects of amino acid supplementation on their performances. Treatments were 1) 18% CP diet (control); 2) 15% CP+0.28% Lys (B, 15L); 3) B+0.06% Met (15LM); 4) B+0.13% Thr (15LT) ; 5) B+0.06% Met+0.13% Thr (15LMT); 6) B+0.06% Met+0.13% Thr+0.05% Trp (15LMTT). Each treatment had 4 replicates with 5 pigs per replicate. The daily weight gains were statistically similar in 15LMT, 15LMTT and control groups. Threonine and methionine supplementation resulted in improved growth performance and nutrient digestibilities, while tryptophan supplementation had little beneficial effect. However, the best feed conversion was found in the control group. Dry. matter and CP digestibilities were improved in the 15LMT and 15LMTT groups. Gross energy, crude fat and phosphorus digestibilities were not affected by the treatment. Among the 15% CP groups, nitrogen digestibility showed the tendency to be increased as the more synthetic amino acids were added. Dry matter and nitrogen excretions were significantly reduced by feeding low protein, amino acid fortified diets, while phosphorus excretion was not influenced. Essential amino acids digestibility was higher in 15LT, 15LMT and 15LMTT groups and lower in the control. The 15LT group showed the best lysine digestibility, and methionine digestibilities were higher in all treated groups than control one. Threonine digestibilities higher in 15LT 15LMT, and 15LMTT than the control. The result shows that threonine and methionine should be added to the diet containing 15% CP diet, fortified with lysine to get same performance of 18% CP diet.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.136-141
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• 1988

Susceptibility of a thermophilic strain (D-71) of Saccharomyces cerevisiae and an osmotolerant strain (SR-S) of Zygosaccharomyces rouxii to Zymolyase-20T were studied in various renditions. Content of glucan and mannan in cell wall of Saocharomyces cerevisiae D-71 were 14.5% and 14.8%, and Zygosaccharomyces rouxii SR-S were 24.0% and 19.0%, respectively. Susceptibility of Saccharomyces cerevisiae D-71 cultured in Wickerham synthetic medium containing 0.5% of methionine and 0.1% of glucose to Zymolyase-20T was 66%, and $K_2$HPO$_4$ and aminobenzoic acid were greatly effective to susceptibility. Susceptibility of Zygosaccharomyces rouxii SR-S cultured in Wickerhnin synthetic medium containing 0.5% of peptone, 0.15% of methionine and 0.l% of glucose to Zymolyase-20T was 80%, and KI and pyridoxine were greatly effective to susceptibility. Susceptibility of Saccharomyces cerevisiae D-71 stationary cultured in YMPG medium at $25^{\circ}C$ for 12 hours was 16o1e and Zygosaccharomyces rouxii SR-S stationary cultured in YMPG medium at $25^{\circ}C$ for 30 hours was 82%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.128-134
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• 2014

To develop a crab-like flavorant from snow crab cooker effluent (SCCE, $20^{\circ}Brix$), optimal reaction conditions were determined using response surface methodology (RSM) combined with reaction flavoring technology (RFT). Using five variables (proline, glycine, arginine, methionine, fructose), RSM based on a five-level central composite design was applied to evaluate sensory acceptance (odor, taste, and overall acceptance) as dependent variables. A model equation obtained from RSM showed 0.88 of R-square for odor, 0.90 for taste, and 0.95 for overall acceptance with 0.07 lack of fit in overall acceptance (P<0.05). Odor score (predicted value) was 7.21 in the saddle point. Optimal flavoring conditions for making a crab-like flavorant were as follows: addition of 0.29 g of proline, 0.63 g of glycine, 0.61 g of arginine, 0.02 g of methionine, and 1.07 g% (w/v) of fructose into SCCE with RFT (90 min at $130^{\circ}C$). Odor score obtained under optimal conditions was 7.56, which was higher than the predicted value.