疎水性アミノ酸

WordNet

street name for lysergic acid diethylamide (同)back breaker, battery-acid, dose, dot, Elvis, loony toons, Lucy in the sky with diamonds, pane, superman, window pane, Zen
any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt
having the characteristics of an acid; "an acid reaction"
lacking affinity for water; tending to repel and not absorb water; tending not to dissolve in or mix with or be wetted by water
abnormally afraid of water (同)aquaphobic
pertaining to or containing any of a group of organic compounds of nitrogen derived from ammonia (同)aminic
the radical -NH2 (同)amino_group

PrepTutorEJDIC

酸性の / 酸味のある,すっぱい(sour) / (言葉・態度などが)厳しい,しんらつな / 酸 / すっぱいもの / 《俗》=LSD

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1. フェニルケトン尿症の概要 overview of phenylketonuria
2. 先天性代謝異常：分類 inborn errors of metabolism classification
3. 乳児および小児における低血糖に対するアプローチ approach to hypoglycemia in infants and children
4. 尿素サイクル障害：臨床的特徴および診断 urea cycle disorders clinical features and diagnosis
5. 先天性代謝異常：代謝性救急疾患 inborn errors of metabolism metabolic emergencies

English Journal

Tryptophan 19 residue is the origin of bovine β-lactoglobulin fluorescence.

Albani JR1, Vogelaer J2, Bretesche L2, Kmiecik D2.Author information 1Laboratoire de Biophysique Moléculaire, Université des Sciences et Technologies de Lille, Bâtiment C6, 59655 Villeneuve d'Ascq Cédex, France. Electronic address: Jihad-Rene.Albani@univ-lille1.fr.2Laboratoire de Biophysique Moléculaire, Université des Sciences et Technologies de Lille, Bâtiment C6, 59655 Villeneuve d'Ascq Cédex, France.Abstractβ-Lactoglobulin consists of a single polypeptide of 162 amino acid residues with 2 Trp residues, Trp 19 present in a hydrophobic pocket and Trp 61 present at the surface of the protein near the pocket. This study aimed to characterize the respective contribution of the two Trp residues to the overall fluorescence of the protein. We added for that calcofluor white, an extrinsic fluorophore, which, at high concentration compared to that of the protein, quenches completely emission of hydrophobic Trp residue(s). The study was performed at different pHs by recording fluorescence steady state spectra and measuring fluorescence lifetimes of the Trp-residues using Single Time Photon Counting method. Our results indicate that addition of calcofluor white does not induce a red shift of the tryptophan(s) emission peak (332nm) but only a decrease in the fluorescence intensity. This means that Trp 61 residue does not contribute to the protein emission, tryptophan emission occurs from Trp 19 residue only. Also, excitation spectrum peak position (283nm) of β-lactoglobulin is not modified upon calcofluor white binding. These results mean that structural rearrangements within β-lactoglobulin are not occurring upon calcofluor white binding. Energy transfer between Trp 19 residue and calcofluor white occurs with 100% efficiency, i.e. the two fluorophores are very close one to each other (<5Å). This energy transfer is not Forster type. Fluorescence intensity decay of Trp 19 residue occurs with three lifetimes, equal to 0.48, 1.49 and 4.29ns at pH 2 (monomeric state). Very close values were obtained at the different studied pHs (2-12) and where β-lactoglobulin is at different quaternary structure or present in solution in a mixture of dimers and monomers. Our data are interpreted as the results of emission occurring from different substructures of the tryptophan, reached at the excited state. The populations of these substructures characterized by the pre-exponential parameters of the fluorescence lifetimes are dependent on the microenvironment of the fluorophore and on the local protein structure.
Journal of pharmaceutical and biomedical analysis.J Pharm Biomed Anal.2014 Mar 25;91:144-50. doi: 10.1016/j.jpba.2013.12.015. Epub 2014 Jan 3.
β-Lactoglobulin consists of a single polypeptide of 162 amino acid residues with 2 Trp residues, Trp 19 present in a hydrophobic pocket and Trp 61 present at the surface of the protein near the pocket. This study aimed to characterize the respective contribution of the two Trp residues to the overa
PMID 24463042

Effects of additional cysteine in fish diet on mercury concentration.

Mok WJ, Hatanaka Y, Seoka M, Itoh T, Tsukamasa Y, Ando M.Author information Department of Fisheries, Kinki University, Nakamachi 3327-204, Nara 631-8505, Japan; Faculty of Fisheries and Aqua-Industry, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia. Electronic address: mokwj@yahoo.com.AbstractMercury contamination, especially of seafood, continues to attract public concern. Cysteine, NH2CH(CH2SH)COOH, is a naturally occurring hydrophobic amino acid that contains a thiol group. The purpose of our study was to investigate the use of the additive cysteine in fish diets to reduce mercury concentration in fish, and to observe the effectiveness of dietary cysteine in fish livers. Diets containing 1% and 10% cysteine successfully decreased mercury concentrations in fish compared with the 0% cysteine diet. The liver may have formed excessive lipid droplets or was unable to mobilize lipid stores during exposure to mercury; additional cysteine could help to mobilize excessive lipids in it.
Food chemistry.Food Chem.2014 Mar 15;147:340-5. doi: 10.1016/j.foodchem.2013.09.157. Epub 2013 Oct 8.
Mercury contamination, especially of seafood, continues to attract public concern. Cysteine, NH2CH(CH2SH)COOH, is a naturally occurring hydrophobic amino acid that contains a thiol group. The purpose of our study was to investigate the use of the additive cysteine in fish diets to reduce mercury con
PMID 24206728

Structure and mechanism of kynureninase.

Phillips RS.Author information Department of Chemistry, University of Georgia, Athens, GA 30602, United States; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, United States. Electronic address: plp@uga.edu.AbstractThe kynurenine pathway is the major pathway of l-tryptophan catabolism in eukaryotes and some bacteria. In this pathway, kynureninase catalyzes the hydrolysis of l-kynurenine (in bacteria) or 3-hydroxy-l-kynurenine (in eukaryotes) to give anthranilic acid or 3-hydroxyanthranilic acid, respectively, and l-alanine. Kynureninase is a member of the aminotransferase superfamily and contains pyridoxal-5'-phosphate (PLP) as cofactor. The enzyme is a dimer of two identical subunits, with the active site containing residues contributed from both subunits. The reaction of kynureninase is formally a retro-Claisen reaction, and thus requires extensive acid-base catalysis. The pH dependence of the reaction of Pseudomonas fluorescens kynureninase shows two pKa's, a base with 6.5 and an acid with 8.8, on kcat/Km, and one pKa of 6.8 on kcat. The effects of mutagenesis of Tyr-226 and 31P NMR results suggest that the basic group with pKa of 6.5 is the phosphate group of the PLP, which accepts a proton from the amino acid substrate zwitterion to initiate transaldimination. The external aldimine of kynurenine and PLP is then deprotonated by the ε-amino group of Lys-227 to give a quinonoid intermediate, which is reprotonated at C-4' to give a ketimine. Addition of water to the γ-carbonyl, assisted by Lys-227, then gives a gem-diol, which undergoes Cβ-Cγ cleavage to give the first product, anthranilic acid, and an enamine intermediate. The enamine is protonated at the β-carbon, resulting in a pyruvate ketimine. Deprotonation at C-4' and reprotonation of the α-carbon gives the external aldimine of l-alanine, which releases the second product, l-alanine. The reaction specificity of kynureninases is determined in part by active site residues, Trp64, Gly281, and Thr282 in P. fluorescens, and the homologous His102, Ser332, and Asn333 in human kynureninase. Asn333 can form a hydrogen bond to the 3-OH of 3-hydroxykynurenine in the human enzyme. Halogenation of kynurenine at C-5 increases activity with both enzymes, but halogenation at C-3 only increases activity for human kynureninase. The effect of halogenation at C-5 may be due to hydrophobic or van der Waals effects, and the effect of halogenation at C-3 for the human enzyme may be due to halogen bonding.
Archives of biochemistry and biophysics.Arch Biochem Biophys.2014 Feb 15;544C:69-74. doi: 10.1016/j.abb.2013.10.020. Epub 2013 Nov 4.
The kynurenine pathway is the major pathway of l-tryptophan catabolism in eukaryotes and some bacteria. In this pathway, kynureninase catalyzes the hydrolysis of l-kynurenine (in bacteria) or 3-hydroxy-l-kynurenine (in eukaryotes) to give anthranilic acid or 3-hydroxyanthranilic acid, respectively,
PMID 24200862

Japanese Journal

Versatile Nuclear Localization Signal-Based Oligopeptide as a Gene Vector

Kanazawa Takanori,Yamazaki Mamiko,Fukuda Tsunehiko [他],Takashima Yuuki,Okada Hiroaki
Biological and Pharmaceutical Bulletin 38(4), 559-565, 2015
… To develop a versatile nuclear-targeted gene vector, nuclear localization signal (NLS) oligopeptides combining cysteine (C), histidine (H), and stearic acid (STR) were investigated in this study. … As a result, C and STR enhanced formation of a smaller and more stable nano-complex with pDNA based on ionic interactions, the disulfide linkage and hydrophobic interactions. …
NAID 130005062274

量子ビームで見るタンパク質の水和現象

吉田亨次,山口敏男
分析化学 64(4), 283-293, 2015
本論文では，タンパク質分子と水分子のかかわりを明らかにするために量子ビーム（放射光や中性子線など）を用いて水和タンパク質やタンパク質水和水の構造とダイナミクスを観測した研究例について報告する．前半ではタンパク質近傍の水について放射光のX線非弾性散乱実験により集団ダイナミクスを調べた結果を示す．中性子散乱により観測される単一粒子の運動では，水和によりタンパク質のダイナミクスが大きく変化することがこれ …
NAID 130005060614

Hydration and hydrogen bond network of water around hydrophobic surface investigated by terahertz spectroscopy.

Shiraga K,Suzuki T,Kondo N,Ogawa Y
The Journal of chemical physics 141(23), 2014-12-21
… Water conformation around hydrophobic side chains of four amino acids (glycine, L-alanine, L-aminobutyric acid, and L-norvaline) was investigated via changes in complex dielectric constant in the terahertz (THz) region. … Each of these amino acids has the same hydrophilic backbone, with successive additions of hydrophobic straight methylene groups (-CH2-) to the side chain. …
NAID 120005530946