• Journal of Plant Biology
• /
• 제31권3호
• /
• pp.197-203
• /
• 1988

The rates of photorespiration and total CO2 fixation depending on leaf ages of spinach (Spinacia oleracea L.) were investigated. Metabolic rates of glycolate and glyoxylate in isolated peroxisomes were also measured. The rate of photorespiration and total CO2 fixation ability increased with the maturing of leaf, but decreased with senescence. Activities of enzymes involved in the peroxisomal photorespiratory pathway such as catalase, glycolate oxidase, NADH-glyoxylate reductase and glutamate-glyoxylate transaminase were highest in the mature leaf, but also decreased with aging of leaf. Glutamate-glyxolate transaminase activity significantly decreased with senescence, especially. the metabolic rate of glycolate was observed to be lower than that of glyoxylate in isolated peroxisomes. Glycolate seemed to be metabolized mainly to glycine, however, it also oxidized to CO2 when glycolate was supplied as a substrate for glycine synthesis instead of glyoxylate. The conversion rates of glycolate and glyxylate into CO2 increased with the senescence of leaves.

• Archives of Pharmacal Research
• /
• 제18권6호
• /
• pp.458-461
• /
• 1995

+To prove uniqueness of allylic alcohol formation from ${\alpha},{\beta}-unsaturated$ ketones by mammal enzymes, a metabolic pattern of dehydroparadols, non-pungent synthetic analogs of shogaol by Aspergillus niger was examined. Two biotransformation products of a dehydroparadol, 1-(4hydroxy-3-methoxyphenyl)-non-1-en-3-one were accumulated in the culture broth of A. niger. They were characterized as 1-(4-hydroxy-3-methoxyphenyl)-non-1-en-9-01-3-one and 1-(4-hydroxy-3-methoxyphenyl)-nonan-9-o1-3-one by UV, NMR and mass spectroscopic analyses. Accumulation of allylic alcohol metabolites was not observed.

• Journal of Microbiology and Biotechnology
• /
• 제17권2호
• /
• pp.218-225
• /
• 2007

A lactic acid bacterium capable of anaerobic respiration was isolated from soil with ferric iron-containing glucose basal medium and identified as L. garvieae by using 16S rDNA sequence homology. The isolate reduced ferric iron, nitrate, and fumarate to ferrous iron, nitrite, and succinate, respectively, under anaerobic $N_2$ atmosphere. Growth of the isolate was increased about 30-39% in glucose basal medium containing nitrate and fumarate, but not in the medium containing ferric iron. Specifically, metabolic reduction of nitrate and fumarate is thought to be controlled by the specific genes fnr, encoding FNR-like protein, and nir, regulating fumarate-nitrate reductase. Reduction activity of ferric iron by the isolate was estimated physiologically, enzymologically, and electrochemically. The results obtained led us to propose that the isolate metabolized nitrate and fumarate as an electron acceptor and has specific enzymes capable of reducing ferric iron in coupling with anaerobic respiration.

• 한국축산식품학회지
• /
• 제42권3호
• /
• pp.351-371
• /
• 2022

Milk fats are present as globules emulsified in the aqueous phase of milk and stabilized by a delicate membrane architecture called milk fat globule membrane (MFGM). The unique structure and composition of the MFGM play an important role in fat digestion and the metabolic programming of neonates. The objective of this review is to compare the structure, composition, and physicochemical characteristics of fat globules in human milk, bovine milk, and infant formula. It provides an overview of the fat digestion process and enzymes in healthy infants, and describes the possible roles of the MFGM in association with factors affecting fat digestion. Lastly, the health benefits of the MFGM on infant nutrition and future perspectives are discussed with a focus on brain development, metabolic response, and gut health.

• BMB Reports
• /
• 제42권7호
• /
• pp.393-400
• /
• 2009

High-density lipoprotein (HDL) is a proven biomarker for the monitoring of changes in antioxidant and anti-inflammation capability of body fluids. The beneficial virtues of HDL are highly dependent on its lipids and protein compositions, and their ratios. In normal state, the HDL particle is enriched with lipids and several HDL-associated enzymes, which are responsible for its antioxidant activity. Lower HDL-cholesterol levels (<40 mg/dL) have been recognized as an independent risk factor for coronary artery disease, as well as being a known component of metabolic syndrome. Functional and structural changes of HDL have been recognized as factors pivotal to the evaluation of HDL-quality. In this review, I have elected to focus on the functional and structural correlations of HDL and the roles of HDL-associated apolipoproteins and enzymes. Recent clinical applications of HDL have also been reviewed, particularly the therapeutic targeting of HDL metabolism and reconstituted HDL; these techniques represent promising emerging strategies for the treatment of cardiovascular disease, for drug or gene therapy.

• Molecules and Cells
• /
• 제25권2호
• /
• pp.312-316
• /
• 2008

Flavanone $3{\beta}$-hydroxylases (F3H) are key enzymes in the synthesis of flavonol and anthocyanin. In this study, three F3H cDNAs from Oryza sativa (OsF3H-1 ~3) were cloned by RT-PCR and expressed in E. coli as gluthatione S-transferase (GST) fusion proteins. The purified recombinant OsF3Hs used flavanone, naringenin and eriodictyol as substrates. The reaction products with naringen and eriodictyol were determined by nuclear magnetic resonance spectroscopy to be dihydrokaempferol and taxifolin, respectively. OsF3H-1 had the highest enzymatic activity whereas the overall expression of OsF3H-2 was highest in all tissues except seeds. Flavanone $3{\beta}$-hydroxylase could be a useful target for flavonoid metabolic engineering in rice.

• 한국연초학회지
• /
• 제4권1호
• /
• pp.1-5
• /
• 1982

The metabolic enzymes, nitrate reductase, amylase and peroxidase and the Photorespiratory enzyme, Slycolate oxidise in Nicotiana tabacum varieties were studied at various growth stages. The enzyme activities of young leaves with rapid growth were different from those of old ones with stationary growth. In young leaves, activity of nitrate reductase was higher than that in mature ones and amylase activity was fairly constant in all stages. Activities of glycolate oxidise and peroxidase were found to be significantly lower in young leaves than in mature ones. Activity of glycolate oxidase in mature middle leaves was 2.45 times higher than that of young ones and inhibited by 36% when the enzyme was treated with 0.16 mM isonicotinic hydrazide.

• 약학회지
• /
• 제30권2호
• /
• pp.62-67
• /
• 1986

It was attempted to observe the effect of garlic on the hepatic purine metabolizing enzymes in this study. The activities of adenosine deaminase, guanase, and uricase in rats were not changed significantly following the feeding of 5% garlic juice. Whereas, garlic juice inhibited significantly the hepatic xanthine oxidase activity compared to control group with the lapse of treated-period. The orate level of serum in rats was significantly decreased by the treatment of garlic juice. The above inhibitory effect of garlic was greater in boiled garlic juice than fresh garlic juice-treated group. These results indicated that, according to the chemical properties of allicin which is unstable in heat, other components than allicin in garlic may regulate the hepatic purine metabolizing enzymes.

• 약학회지
• /
• 제51권1호
• /
• pp.75-82
• /
• 2007

Reactive oxygen species (ROS) are produced in the metabolic process of oxygen in cells. The superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in cells systemize the antioxidant enzymes to control the oxidative stress. Genistein is one of the isoflavonoids, and its role in controlling cellular oxidative stress is presently the active issue at question. In this study; we analyzed genistein-induced survival rates of the CHO-K1 cells, activities of antioxidant enzymes, ROS levels, and expression levels of antioxidant enzyme genes in order to investigate the effect of genistein on cellular ROS production and antioxidative systems in CHO-K1 cells. As results, the survival rate of cells was decreased as the dose of genistein increases (12.5${\sim}$200 ${\mu}$M). Genistein increased cellular ROS levels, while it reduced total SOD activities and the expression of CuZnSOD. In conclusion, we suggest that genistein may induce oxidative stress via down-regulation of SOD.

• Journal of Plant Biology
• /
• 제29권2호
• /
• pp.85-94
• /
• 1986

Canavanine content of the cotyledons of Canavalia lineata decreased gradually during germination and growth of seedlings but continued to increase in roots and leaves. After abscission of cotyledons, canavanine content of leaves depleted competely. The activity of canavanase could be detected in leaves and roots, but not in cotyledons. High arginase activity was observed in the cotyledons of seeds at the earlyimbibition period. During the growth of seedlings, cotyledonary canavanine appeared to be transported to the growing of seedlings where it could be utilized through nitrogen metabolic pathways. In crude cell-free extracts of leaves, maximum activities of canavanase or arginase appeared in 30mM Tris-HCl buffer (pH 9.0) or 30mM NaHCO3 buffer (pH 10.0), respectively. The activities of these two enzymes differed from each other when treated with Co2+ or Mn2+. These results support the idea that canavanase and arginase might be different enzymes.