• Title/Summary/Keyword: Catabolism

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A Possible Enzymatic Catabolism of L-Ascorbic Acid via $\alpha$-Ketoaldehydes (L-Ascorbic Acid의 생체분해)

  • 강사욱
    • Korean Journal of Microbiology
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    • v.23 no.4
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    • pp.302-308
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    • 1985
  • It is shown by means of nuclear magnetic resonance spectroscopy that 3,4,5-trihydroxy-2-keto-L-valeraldehyde (L-xylosone), an ${\alpha}$-ketoaldehyde, is formed during the oxidative catabolism of L-ascorbic acid. It is proposed that this substance serves as a substrate for the glyoxalase system by which it is transformed to L-xylonic acid. As L-xylonic acid is further oxidized to L-erythroascorbic acid, a biochemical pathway is proposed for the action of vitamin C which consists of two further ${\gamma}$-lactones and three different substrates of the glyoxalase system.

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Kinetic and Structural Characterization for Cofactor Preference of Succinic Semialdehyde Dehydrogenase from Streptococcus pyogenes

  • Jang, Eun Hyuk;Park, Seong Ah;Chi, Young Min;Lee, Ki Seog
    • Molecules and Cells
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    • v.37 no.10
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    • pp.719-726
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    • 2014
  • The ${\gamma}$-Aminobutyric acid (GABA) that is found in prokaryotic and eukaryotic organisms has been used in various ways as a signaling molecule or a significant component generating metabolic energy under conditions of nutrient limitation or stress, through GABA catabolism. Succinic semialdehyde dehydrogenase (SSADH) catalyzes the oxidation of succinic semialdehyde to succinic acid in the final step of GABA catabolism. Here, we report the catalytic properties and two crystal structures of SSADH from Streptococcus pyogenes (SpSSADH) regarding its cofactor preference. Kinetic analysis showed that SpSSADH prefers $NADP^+$ over $NAD^+$ as a hydride acceptor. Moreover, the structures of SpSSADH were determined in an apo-form and in a binary complex with $NADP^+$ at $1.6{\AA}$ and $2.1{\AA}$ resolutions, respectively. Both structures of SpSSADH showed dimeric conformation, containing a single cysteine residue in the catalytic loop of each subunit. Further structural analysis and sequence comparison of SpSSADH with other SSADHs revealed that Ser158 and Tyr188 in SpSSADH participate in the stabilization of the 2'-phosphate group of adenine-side ribose in $NADP^+$. Our results provide structural insights into the cofactor preference of SpSSADH as the gram-positive bacterial SSADH.

Genes for the Catabolism of Deoxyfructosyl Glutamine in pAtC58 Are Attributed to Utilization of Octopine in Agrobacterium tumefaciens Strain NT1

  • Baek, Chang-Ho;Park, Dae-Kyun;Lee, Ko-Eun;Hwang, Won;Kim, In-Hwang;Maeng, Jue-Son;Kim, Kun-Soo
    • Journal of Microbiology and Biotechnology
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    • v.14 no.4
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    • pp.822-828
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    • 2004
  • Nopaline-type Agrobacterium tumefaciens strain C58 cannot utilize octopine (Oct) as the sole carbon and nitrogen sources. This strain harbors two plasmids; a virulent plasmid, pTiC58, and a megaplasmid, pAtC58. From strain NT1, which is a derivative of C58 harboring only pAtC58, we isolated spontaneous mutants that utilize Oct as the sole nitrogen source. These Oct-catabolizing mutants, however, could not utilize the opine as the sole carbon source. In contrast, strain UIA5, a plasmid-free derivative of C58, could not give rise to such mutants. The mutations isolated from NT1 were mapped to socR in pAtC58, which is a negative regulator of the soc operon responsible for the uptake and catabolism of an Amadori opine, deoxyfructosyl glutamine (Dfg). A derivative of UIA5 carrying a clone of the soc operon with a transposon inserted in socR also utilizes Oct as the sole nitrogen source. However, UIA5 harboring the operon with mutations in each of the structural genes in the soc operon, socA, B, C, and D, lost the ability to generate spontaneous Oct-utilizing mutants, suggesting that soc genes in pAtC58 are required for the utilization of Oct as a nitrogen source, and that derepressed expression of these genes allows cells to utilize Oct. In contrast, Oct-catabolizing mutants derived from C58, which grew using Oct as the sole nitrogen source, could also utilize the opine as the sole carbon source. These mutants did not carry any detectable mutations in socR or the region upstream to the gene in pAtC58, suggesting that mutations occurring elsewhere in the genome, most likely in pTiC58, allow the uptake and catabolism of the opine.

Correlation between Eum, Yang, Ki and Blood Metabolism and Obesity (음양기혈대사(陰陽氣血代謝)와 비만(肥滿)의 상관관계)

  • Shin, Soon Shik
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.33 no.1
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    • pp.1-9
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    • 2019
  • This paper aims to present a model of obesity and leanness based on eum, yang, ki and blood metabolism of Korean medicine. I analyzed the theory of eum, yang, ki and blood metabolism, yang transforming ki and eum forming the body on Korean medicine, and compared them with energy homeostasis by anabolism and catabolism of modern medicine. In the eum and yang theory, the metabolic process of the human body is dominated by synergism and antagonism between eum force and yang force. When the balance of eum and yang collapses, all the pathological actions of the human body appear, and in the eum and yang metabolic process, an imbalance between yang transforming ki and eum forming the body occurs. The function of yang transforming ki is reduced to ki deficiency, and the function of eum forming the body is increased to blood excess. When blood excess and ki deficiency is given, energy intake increases, energy expenditure decreases, overweight and obesity occur. On the contrary, the function of yang transforming ki is increased to ki excess, and the function of eum forming the body is decreased to blood deficiency. When ki excess and blood deficiency is done, energy intake decreases and energy expenditure increases, the body becomes leanness. When the balance of eum, yang, ki and blood metabolism collapses and becomes blood excess and ki deficiency, overweight and obesity occur, and when ki excess and blood deficiency is done, the body becomes leanness. The energy homeostasis of the human body can be explained by eum, yang, ki and blood metabolism of Korean medicine and it contains the concept of anabolism and catabolism of modern medicine.

"Dietary supplementation of L-tryptophan" increases muscle development, adipose tissue catabolism and fatty acid transportation in the muscles of Hanwoo steers

  • Priatno, Wahyu;Jo, Yong-Ho;Nejad, Jalil Ghassemi;Lee, Jae-Sung;Moon, Jun-Ok;Lee, Hong-Gu
    • Journal of Animal Science and Technology
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    • v.62 no.5
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    • pp.595-604
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    • 2020
  • This study investigated the effects of dietary rumen-protected L-tryptophan (TRP) supplementation (43.4 mg of L-tryptophan kg-1 body weigt [BW]) for 65 days in Hanwoo steers on muscle development related to gene expressions and adipose tissue catabolism and fatty acid transportation in longissimus dorsi muscles. Eight Hanwoo steers (initial BW = 424.6 kg [SD 42.3]; 477 days old [SD 4.8]) were randomly allocated to two groups (n = 4) of control and treatment and were supplied with total mixed ration (TMR). The treatment group was fed with 15 g of rumen-protected TRP (0.1% of TMR as-fed basis equal to 43.4 mg of TRP kg-1 BW) once a day at 0800 h as top-dressed to TMR. Blood samples were collected 3 times, at 0, 5, and 10 weeks of the experiment, for assessment of hematological and biochemical parameters. For gene study, the longissimus dorsi muscle samples (12 to 13 ribs, approximately 2 g) were collected from each individual by biopsy at end of the study (10 weeks). Growth performance parameters including final BW, average daily gain, and gain to feed ratio, were not different (p > 0.05) between the two groups. Hematological parameters including granulocyte, lymphocyte, monocyte, platelet, red blood cell, hematocrit, and white blood cell showed no difference (p > 0.05) between the two groups except for hemoglobin (p = 0.025), which was higher in the treatment than in the control group. Serum biochemical parameters including total protein, albumin, globulin, blood urea nitrogen, creatinine phosphokinase, glucose, nonesterified fatty acids, and triglyceride also showed no differences between the two groups (p > 0.05). Gene expression related to muscle development (Myogenic factor 6 [MYF6], myogenine [MyoG]), adipose tissue catabolism (lipoprotein lipase [LPL]), and fatty acid transformation indicator (fatty acid binding protein 4 [FABP4]) were increased in the treatment group compared to the control group (p < 0.05). Collectively, supplementation of TRP (65 days in this study) promotes muscle development and increases the ability of the animals to catabolize and transport fat in muscles due to an increase in expressions of MYF6, MyoG, FABP4, and LPL gene.