• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.315-318
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• 1995

Sulfanilic acid (4-aminobenzenesulfonic acid) alone is normally not permeant in bacteria but can be readily delivered via the microbial dipeptide transport system. A dipeptidyl derivative of this compound, L-phenylalanyl-L-2-sulfanilylglycine (PSG), prepared by attachment of its primary amino group to the phenylalanyl $\alpha$-glycine moiety, appeared to have a Km of 0.125 mM and a Vmax of 1.9 nmoles/ml/min ($A_{660}$, 1.0) in Escherichia coli. From competitive spectrophotometric analysis, it was found that the type of amino acids in both of the N- and C-terminals affected the kinetic power of dipeptides. The growth inhibitory effect of PSG was over 7 times more potent than that of the sulfanilic acid against E. coli, suggesting that this potential inhibition was presumably due to the increased hydrophobic nature of the sulfanilyl dipeptide.

• 식물조직배양학회지
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• 제22권3호
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• pp.137-142
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• 1995

생리적인 pH에서 음전하를 띄우고 있는 산성 아미노산인 aspartate와 glutamate는 다른 중성 아미노산과 경쟁방해 실험을 행한 연구결과에 의하면 이들도 중성 아미노산이 갖는 능동운반계와 동일한 운반자를 소유한다. 중성 아미노산을 아미노산 한 분자 당 한개의 수소이온과 동반수송되고 전하에 보상을 위해서 한 분자 당 한개의 칼륨 이온을 배출한다. 그러나 산성 아미노산은 한 분자 당 2개의 수소이온과 동반수송되고, 한 분자 당 칼륨 한 분자를 배출한다. 중성 아미노산과 같은 운반계를 소유하고, 2개의 수소이온과 동반수송되는 능동운반계는 본 실험에서 처음으로 보고된다. 이 결과로부터 두개의 동반수송된 수소이온 중 한 개는 산성 아미노산에 있는 pK$_3$카르복실기를 먼저 중화시킨 후에 중성화된 형태로 수소이온 한 분자와 동반수송된다고 사료된다. 그러므로 유채는 20개의 아미노산에 대해서 다만 2개의 운반계, 즉 일반- 과 알카리성 아미노산 운반계를 가진 것으로 확인되었다. 다른 식물에서 이미 보고된 결과들을 참고하여 아미노산 운반계의 진화적인 의미를 고찰하였다.

• 미생물학회지
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• 제16권4호
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• pp.148-154
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• 1978

Saccharomyces cerevisiae J170, a mutant, was used for $DL-^{14}C-leucine$ uptake during the sporulation and vegetative stage. $^{14}C-Leucine$ uptake into yeast cells appeared the highest at pH 6.0, indicating the same result of glucose transport, $^{14}C-Leucine$ uptake in sporulation period was higher than in growth phase, showing the evidence that leucine is more required for protein synthesis. This tendency has the evidence tht leucine is more required for protein synthesis. This tendency has the evidence that leucine is more required for protein synthesis. This tendency has been also supported from the result of Km values of leucine uptake in two stages of yeast. Leucine uptake was inhibited by 2,4-dinitrophenol in two stages of yeast. This means that leucine transport system is associated with energy dependent in both stages. The contents of all amino acid in growth phase cells were higher than those of sporulation stge cells, and those of methionine and tyrosine were showed in trace during the sporulation stage. In contrast, the content of glutamic acid in sporulation stage was compared with those of other amino acids.

• Archives of Pharmacal Research
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• 제6권2호
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• pp.109-114
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• 1983

A mechanism of taurine transfer across the rat small intestine was elucidated by using the in situ recirculation perfusion or loop method. Taurine uptake was saturable, Km= 39.9 mM, and energy dependent, and required sodium. The close structural analogues, aminomethane sulfonic acid, .gamma.-amino-butyric acid, hypotaurine, and .betha.-alanine, reduced significantly taurine uptake when present in 10-fold excess. The .alpha.-amino acid, glycine, did not inhibit uptake. Hence, all of these findings lead to a conclusion that a carrier-mediated transport system for taurine exists in the small intestine.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2019년도 춘계학술대회
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• pp.9-9
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• 2019

• Asian-Australasian Journal of Animal Sciences
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• 제19권9호
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• pp.1361-1368
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• 2006

Amino acid imbalances refer to the deleterious effects that occur when a second-limiting amino acid or mixture of amino acid lacking a particular limiting amino acid is supplemented in diets marginal in one or more indispensable amino acids. In spite of variation in the conditions that have been used to induce amino acid imbalances, such as protein level in the diet, the extent of difference in total nitrogen content between basal and imbalanced diets, and kinds of amino acids used as imbalancing agents, the conspicuous common features of amino acid imbalances have been a decreased concentration of the limiting amino acid in blood, depression of feed intake and weight gain, and increased dietary content of the limiting amino acid needed to correct the imbalances. There is strong evidence that a decrease in the concentration of a limiting amino acid detected in the anterior prepyriform cortex of the brain is followed by behavioral effects, especially a decrease in feed intake. This might be due to the competition between the limiting amino acid and the amino acids in the imbalancing mixture for transport from blood into brain. One of the biochemical responses of animals fed amino acid imbalanced diets is a rapid decrease in the concentration of the limiting amino acid, which are due in part to an increase in catabolism of the limiting amino acid by the increased activities of enzymes involved in the catabolism of the amino acid. Practically, specific amino acid imbalances could be induced in swine and poultry diets that have been supplemented with lysine, methionine, tryptophan when threonine, isoleucine, valine, etc. are potentially third- or fourth-limiting in diets. In these cases supplementation of the limiting amino acid could be beneficial in preventing the decrease of feed intake that could otherwise occur as a result of amino acid imbalance.

• 대한수의학회지
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• 제37권1호
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• pp.111-117
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• 1997

This study was carried out determine the effect of renal ischemia on amino acid transport in rabbit renal cortical slices. The animal models of renal ischemia induced experimentally by clamping the renal artery. These results were summarized as follows: 1. The uptake of amino acids lysine and ${\alpha}$-aminobutyrate(AIB), dicarboxylate succinate and organic anion PAH in cortical slices was normal or increased after 30 or 60 min of ischemia in vivo. 2. In a 30 min ischemic kidney, the slice uptake of amino acids was returned to the control level by 30 min of reflow. In a 60 or 90 min ischemic kidney, the lysine uptake was returned to the control level after of reflow, but the uptake of AIB and succinate was significantly reduced during reflow period of 30-120 min. 3. Oxygen consumption in cortical slices was increased after 30 min of ischemia but was not altered by 60 min of ischemia. This results indicat that transient ischemia caused increasing of amino acid uptake in renal cortical slices without metabolic disorder of renal proximal tubule.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.34-36
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• 2002

Epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) have been shown to stimulate proliferation and differentiation of various somatic cells, including placental trophoblasts and also to enhance fetal growth and development when maternally administered. Since an increase of the expression of placental EGF and IGF-I receptors in rat, mouse, and human with the gestation advanced, both EGF and IGF-I were considered to play pivotal roles on fetal growth by regulating some function of placental cells. Amino acids are crucial importance for both maternal and fetal requirements of energy source and essential constituent of fetal mass during pregnancy. Impaired fetal and placental uptake of amino acids has been observed in several models of growth retardation in the rat. Amino acid is concentrated in the fetal side through active transport by amino acid transporters and is one of the important metabolic fuels for the fatal growth. Therefore, at first plasma amino acid concentrations in mothers and fetuses were measured as an index of uphill transport across the placenta associated with EGF and IGF-1. The EGF administration at the concentration of 0, 0.1, or 0.2 $\mu\textrm{g}$/g to pregnant rats from day 18 to 21 of gestation apparently increased fetal/maternal ratio of serum proline concentration and also fatal growth in EGF dose-dependent manner. When IGF-I in doses of 0, 1, 2, and 4 $\mu\textrm{g}$/g were administrated, the ratio of leucine, isoleucine, tryptophan, phenylalanine, tyrosine and also fetal growth significantly increased with a dose-dependent manner. These results suggested that EGF and IGF-I enhanced fatal growth by, as one of its possible mechanisms, promoting placental activity to transfer some amino acid supplies from the mother to the fetus in late pregnancy.

• Journal of Pharmaceutical Investigation
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• 제20권4호
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• pp.223-228
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• 1990

The contribution of endogenous transport systems to the blood-brain barrier (BBB) transport of basic and acidic drugs was studied by using a carotid injection technique in rats and an isolated bovine cerebrovascular disease state were compared between the normotensive rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP) which have been well established as an animal model with pathogenic similarities to humans. Basic drugs such as eperisone, thiamine and scopolamine inhibited, in a concentration dependent manner the in vivo uptake of $[{^3}H]choline$ through BBB, whereas amino acids and acidic drugs such as salicylic acid and valproic acid did not inhibit the uptake. The uptake of $[^3H]choline$ by B-CAP increased with time and showed a remarkable temperature dependency. The uptake of $[^3H]choline$ by B-CAP showed the very similar inhibitory effects as observed in the in vivo brain uptake, and was competitively inhibited by a basic drug, eperisone. The in vivo BBB uptakes of $[^3H]acetic$ acid and $[^{14}C]salicylic$ acid were dependent on pH of the injectate and the concentration of drugs. Several acidic drugs such such as salicylic acid, benzoic acid and valproic acid inhibited the in vivo uptake of $[^3H]acetic$ acid, whereas amino acid, choline and a basic drug such as eperisone did not inhibit the uptake. The uptake of acetic acid by B-CAP was competitively inhibited by salicylic acid. The permeability surface area product (PS) through BBB for $[^3H]choline$ in SHRSP was significantly lower than that in WKY. The concentration of choline in the brain dialysate in SHRSP was about half of that in WKY, while no significant difference was observed in the plasma concentration of choline between SHRSP and WKY. No significant difference was observed in the transport of monocarboxylic acids, glucose and neutral amino acid through BBB between SHRSP and WKY. From these results, it was concluded that BBB transport system of choline contributes to the transport of basic drugs through BBB, that acidic drugs can be transported via a moncarboxylic acid BBB transport system and that the specific dysfuntion of the BBB choline transport in SHRSP was ascribed to the reduction of the maximum velocity of choline concentration in the brain interstitial fluids.

• 한국초지조사료학회지
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• 제39권2호
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• pp.75-80
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• 2019

Oilseed rape is known to crop having low nitrogen use efficiency (NUE) but requires high levels of N fertilizer. NUE is associated with N remobilization from source to sink organ, consequently affects seed yield. Remobilization of leaf N is also related to transport of C/N metabolites in phloem. However, interaction between seed yield and phloem transport was not fully documented. In response to seed yield, N and C metabolites and their transport into seed from bolting to pod filling stage investigated in two contrasting genotypes (Capitol and Pollen) cultivated under ample (HN) or limiting nitrate (LN) supply. Seed yield was significantly reduced in N limitation and its reduction rate was much lower in Capitol than in Pollen compared to HN treated plants. Amino acid and protein content was higher in Capitol than in Pollen at bolting stage. They gradually decreased during plant development but not significant between two cultivars and/or two treatments. Glucose, fructose and sucrose content were 1.8-,1.6- or 1.25-fold higher in LN condition than in HN condition, respectively. Amino acid and sucrose content in phloem were largely higher in Capitol than in Pollen under LN condition. These results indicate that the higher seed yield might be related to greater transport ability of amino acid and sucrose in phloem under LN condition.