Wyniki wyszukiwania - Biblioteka Nauki

1

Activity of selected aromatic amino acids in biological systems

100%

Krzyściak W.

Acta Biochimica Polonica

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2011

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tom 58

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nr 4

461-466

EN

Besides the structural function in proteins, aromatic amino acids are precursors of many important biological compounds essential for normal functioning of the human organism. Many of these compounds may be used as markers for identification of specific pathological states. Comprehensive knowledge about the metabolism of aromatic amino acids and mechanisms of action of their metabolites made it possible to develop effective treatments for many disorders. However, it should not be forgotten that in some pathological conditions, these compounds could not only be involved in the pathogenesis of many disease entities but could also be used as an important tool in prediction of many diseases. This paper contains a review of published literature on aromatic amino acids in the context of physiological processes of the human body and chosen social disorders, such as cancers; psychiatric disorders: depression, anxiety states, schizophrenia, bipolar affective disorders; neurodegenerative, and cardiovascular diseases; chronic kidney insufficiency or diabetes.

2

Adsorption of tyrosine on Ag(110) and Ag(111) surfaces

100%

Miłkowska M. , Jurkiewicz-Herbich M.

Polish Journal of Chemistry

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1998

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tom Vol. 72, nr 6

1096-1105

EN

The adsorption of tyrosine at Ag(110) and Ag(111) single crystal electrodes has been studied in aqueous solutions of 0.1 M LiClO4. The standard Gibbs energies of adsorption Delta G(0)-ads, at the potential of maximum adsorption and the interaction parameters, A, using Frumkin's isotherm were calculated. The orientation of the adsorbed tyrosine molecules is different on Ag(111) and Ag(110) electrodes. At Ag(111) the molecules adsorb flat with the benzene ring parallel to the electrode, whereas at Ag(110) electrode the orientation is propably vertical with OH group tawards the metal. The origin of that differences is propably the different atomic structure of both electrodes.

3

Rapid separation of tyrosine - specific tRNA from white lupin

100%

Barciszewska M. Z. , Krajewski J. , Gawronska I. , Barciszewski J.

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nr 2

EN

During Isolation of total rilmnucleic acids from white lupin (Lupinus albus) and their subsequent separation by 10% polyacrylamide gel electrophoresis, a fast migrating RNA band is very well separated. The nucleotide sequence analysis of 76 nucleotide long sequence with many modified nucleosides was found to be identical with that of tyrosine specific tRNA of yellow lupin seeds (Lupinus luteus) and wheat germ (Trtiicum aestivum). Also this tRNATyr is identical with plant amber suppressor tRNA. 'I'he presented approach offers a very rapid method of purification of plant tRNA with UAG suppressor activity.

4

Variation in the analgesic activity of opioid peptide fragments in correlation with the amino acidic sequence

88%

Jaba I. , Tamba B. , Manolidis G. , Mungiu O.

Open Medicine

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2007

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tom 2

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nr 4

417-429

EN

Short fragments of typical or atypical opioid peptides, lacking the whole four amino acid sequence of the enkephalin motif, can preserve a significant percentage of the analgesic activity of the original peptides. This paper investigates the importance of the amino-acidic sequence of minimum structure typical opioid peptides for the analgesic activity. Different groups of rats were treated with 1) Gly-Tyr, 0.5 mg/rat i.t., 2) Tyr-Gly, 0.5 mg/rat i.t., 3) Tyr-Gly-Gly, 0.5 mg/rat i.t., 4) Gly-Gly-Phe-Leu, 0.5 mg/rat i.t., 5) Leu-enkephalin, 0.5 mg/rat i.t.. The analgesic effect of the tested substances was appreciated through the nociceptive threshold for thermal (plantar test) and mechanical nociception (algesimetric test). Fragments of typical opioid peptides elicited antinociceptive activity only when a tyrosine residue was present at the N-terminal end of the amino-acidic sequence. The presence of Nterminal tyrosine provides affinity for the opioid receptors and significant analgesic activity. The intensity of the antinociceptive effect was directly proportional with the length of the amino-acidic sequence. The inhibition of the analgesic effect by previous administration of naloxone proves that this effect is mediated through the opioid system.

5

Synthesis of ring labeled [1'-14C]-L-tyrosine

88%

Kański R. , Augustyniak W. , Kańska M.

Nukleonika

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2006

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tom Vol. 51,suppl.2

13-16

EN

The synthesis of specifically ring labeled isotopomer of L-tyrosine, (l-Tyr), using chemical and enzymatic methods is reported. The carbon-14 labeled [1’-14C]-L-Tyr has been synthesized by a 6-step conversion of [2-14C]-malonic acid into [4’-14C]-phenol and its subsequent condensation with S-methyl-L-cysteine using enzyme tyrosine phenol lyase from Citrobacter freundii.

6

Indirect inactivation of tyrosinase in its action on tyrosine

75%

Munoz-Munoz J. L. , Garcia-Molina F. , Acosta-Motos J. R. , Arribas E. , Garcia-Ruiz P. A. , Tudela J. , Garcia-Canovas F. , Rodriguez-Lopez J. N.

Acta Biochimica Polonica

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2011

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tom 58

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nr 4

EN

Under aerobic conditions, tyrosinase is inactivated by dopa as a result of suicide inactivation, and, under anaerobic conditions, as a result of irreversible inactivation. However, tyrosine protects the enzyme from being inactivated by dopa under anaerobic conditions. This paper describes how under aerobic conditions the enzyme acting on tyrosine is not directly inactivated but undergoes a process of indirect suicide inactivation provoked by reaction with the o-diphenol originated from the evolution of o-dopaquinone and accumulated in the reaction medium.

7

A Fluorescence, 1H NMR spectroscopy and molecular dynamics study of the influence of rotamer population on fluorescence decay of tyrosine, phenylalanine and their derivatives

75%

Ganzynkowicz R. , Liwo A. , Wiczk W.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2001

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tom Vol. 5, No 3

311-316

EN

Molecular dynamics simulations were carried out on tyrosine and phenylalanine and their derivatives with various terminal groups to determine the populations of side-chain rotamers. The obtained populations were compared with those calculated from fluorescence-decay lifetime distributions and NMR studies. It was found that theoretically calculated populations do not match the experimental ones, which suggests that the static rotamer model is inadequate to explain the dynamics of tyrosine and phenylalanine side chain in fluorescence and NMR experiments.

8

Amino acid - induced insulin release from the perfused rat pancreas. The influence of phenylalanine and tyrosine

75%

Mackowiak P.

Acta Physiologica Polonica

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1990

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tom 41

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nr 7

EN

Maćkowiak P.: Amino acid-induced insulin release from the perfused irat pancreas. The influence of phenylalanine and tyrosine. Acta physiol, pol. The effects of L or D phenylalanine and L tyrosine on insulin release from the perfused rat pancreas were investigated. It was found that in the presence of D-glucose, all three amino-acids stimulate insulin secretion. After L-Phe had been removed from perfusate in the presence or absence of L-Tyr, the secondary rise of insulin release (an “off response”) was noticed. This phenomenon did not follow to either D-Phe or L-Tyr.

9

The effect of losartan on Ang II and Ang IV-induced changes in tyrosine protein kinase activity in rat pituitary in vitro

75%

Rebas E. , Lachowicz A.

Cellular and Molecular Biology Letters

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2002

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tom 07

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nr Suppl.

10

Polyphenol oxidase activity in selected apple cultivars

63%

Kolodziejczyk K. , Milala J. , Sojka M. , Kosmala M. , Markowski J.

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tom 18

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nr 2

51-61

EN

Twenty two scab-resistant apple cultivars, harvested in the 2007 and 2008 seasons, were analysed for phenolic compounds content and polyphenol oxidase (PPO) activity. Tyrosine content was determined in the raw juices of five selected cultivars. The results showed substantial differences in the composition between the investigated apple cultivars, particularly in the phenolic compounds contents. Their total polyphenol content ranged from 161.9 to 882.4 mg/kg f.w., with hydroxycinnamic acids as the main phenolic compounds. The level of PPO activity ranged from 5 to 240 U/g f.w. Almost half of the 22 cultivars show PPO activity below 50 U/g f.w. 'Angold', 'Selena' and 'Gold Milenium' showed the highest PPO activity; between 125-133 U/g f.w. 'Rebella', 'Sampion', 'Topaz', 'Rewena', 'Enterprise' and 'Gerlinde' showed the lowest PPO activity. Statistical analysis showed no correlation between PPO activity and total polyphenol content or hydroxycinnamic acids. No correlation can be confirmed between PPO activity and tyrosine content.

PL

Oznaczono zawartość polifenoli i aktywność oksydazy polifenolowej (PPO) w dwudziestu dwóch odmianach jabłek parchoodpornych z sezonów 2007 i 2008. W sokach surowych pięciu wybranych odmian oznaczono zawartość tyrozyny. Wykazano zasadnicze różnice składu badanych odmian, zwłaszcza dotyczące zawartości substancji polifenolowych. Zawartość polifenoli ogółem wynosiła od 161,9 do 882,4 mg/kg ś.m., gdzie głównymi składnikami polifenolowymi były kwasy hydrok- sycynamonowe. Aktywno ść PPO wynosiła od 5 U/g ś.m do 240 U/g ś.m. Ponad połowa z 22 odmian wykazywala aktywno ść PPO poniżej 50 U/g ś.m. Odmiany 'Angold', 'Selena' i 'Gold Milenium' wykazywał najwyższą aktywność PPO pomiędzy 125-133 U/g ś.m., a 'Rebella', 'Szampion', 'Topaz', 'Rewena', 'Enterprise' i 'Gerlinde' najniższą aktywność PPO. Statystyczna analiza danych nie wykazał korelacji pomiędzy aktywnością PPO a zawartością polifenoli ogółem lub zawartością kwasów hydroksycynamonowych. Nie potwierdzono korelacji pomiędzy aktywnością PPO a zawartością tyrozyny.

11

Determination of free and bound amino acids in three strains of Naegleria

63%

Alonso P. , Zubiaur E.

Acta Protozoologica

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1989

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tom 28

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nr 2

12

Melatonin pretreatment does not modify extrasystolic burden in the rat ischemia-reperfusion model

63%

Durkina A. V. , Bernikova O. G. , Mikhaleva N. J. , Paderin N. M. , Sedova K. A. , Gonotkov M. A. , Kuzmin V. S. , Azarov J. E.

Journal of Physiology and Pharmacology

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2021

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tom 72

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nr 1

13

Melanization of Bomirski hamster amelanotic melanoma cells (Ab line) depends on the type of culture medium

63%

Skoniecka A. , Zauszkiewicz-Pawlak A. , Tyminska A. , Cichorek M.

Folia Histochemica et Cytobiologica

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2018

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tom 56

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nr 4

14

Tyrosine and its catabolites: from disease to cancer

63%

Tanguay R. M. , Jorquera R. , Poudrier J. , St-Louis M.

Acta Biochimica Polonica

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1996

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tom 43

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nr 1

EN

Hereditary tyrosinemia type I (HT I, McKusick 276700) is a metabolic disease with a pattern of autosomal recessive inheritance. The disease is caused by a deficiency of the enzyme involved in the last step in the degradation of the amino acid tyrosine, fumarylacetoacetate hydrolase (FAH). The result of this block is the accumulation of catabolites some of which have been proposed to be highly toxic due to their alkylating potential. In humans, hereditary tyrosinemia is often associated with the development of hepatocellular carcinoma in young patients. The reasons for the high incidence of hepatocellular carcinoma are unknown but it has been suggested that it may be caused by accumulated metabolites such as fumarylacetoacetate (FAA) and maieylacetoacetate (MAA). The various mutational defects in the FAH gene are reviewed. The use of two mouse models of this disease to study the molecular basis of the pathologies associated with HT I are discussed. Finally, some preliminary data on the mutagenic potential of FAA and MAA in a gene reversal assay are presented.

15

Peroxynitrite mediator of the toxic action of nitric oxide

63%

Bartosz G.

Acta Biochimica Polonica

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1996

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tom 43

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nr 4

EN

Peroxynitrite (oxoperoxonitrate(-l)), anion of peroxynitrous acid, is thought to mediate the toxic action of nitric oxide and superoxide anion. Peroxynitrite is formed in a fast reaction between these species, reacts with all classes of biomolecules, is cytotoxic, and is thought to be involved in many pathological phenomena. Its main reactions involve one- and two-electron oxidation and nitration. Protein nitration is often used as a footprint of peroxynitrite reactions in vivo. Nitration of tyrosine and of tyrosyl residues in proteins may be an important mechanism of derangement of biochemical signal transduction by this compound. However, apparently beneficial effects of peroxynitrite have also been described, among them formation of nitric oxide and nitric oxide donors in reactions of peroxynitrite with thiols and alcohols.

16

CD45 in memory and disease

63%

Tchilian E. Z. , Beverley P. C. L.

Archivum Immunologiae et Therapiae Experimentalis

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2002

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tom 50

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nr 2

17

Wstępna ocena budowy chemicznej i struktury fazowej nowych samoorganizujących się poli(arylano-estrów) jako systemów dla kontrolowanego uwalniania leków

51%

Gajowy J. , Niemczyk A. , El Fray M.

Engineering of Biomaterials

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2012

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tom Vol. 15, no. 112

6-11

PL

Nowe amfipatyczne poli(arylano-estry) wykazujące samoorganizację makrocząsteczek (w stanie stopionym lub w roztworach) stanowią interesującą grupę materiałów o różnorodnych właściwościach i zastosowaniach m.in. w technikach medycznych jako systemy kontrolowanego uwalniania leków. Głównym celem pracy była wstępna ocena budowy chemicznej i struktury fazowej nowych materiałów polimerowych wykazujących zjawisko samoorganizacji makrocząsteczek. Do określenia budowy chemicznej produktu finalnego wykorzystano metodę spektroskopii w podczerwieni (ATR FTIR), strukturę fazową oceniono na podstawie analiz termogramów DSC, możliwość powstawania micelarnych/nanosferycznych samoorganizujących się struktur oraz krytyczne stężenie micelizacji oceniono metodą spektroskopii UV-VIS. Analiza wyników spektrofotometrycznych potwierdziła budowę chemiczną nowych poli(arylano-estrów) modyfikowanych polieterami o różnych masach molowych. Termogramy DSC wykazały dobrą separację mikrofazową dla materiału modyfikowanego polieterem o masie molowej 2000 g/mol, a krytyczne stężenie micelizacji dla tego materiału określone techniką spektrofotometryczną wyniosło 0,2%(w/v). Przedstawione w pracy wyniki dają podstawę do kontynuacji badań nad modyfikacją otrzymanych poli(arylano-estrów) innymi substancjami (nie tylko polietarami) w celu otrzymania materiałów o jak największej zdolności do samoorganizacji makrocząsteczek.

EN

New amphipathic poly(arylane-ester)s with self-assembling macromolecules (in the melt or in solution) are an interesting group of materials possessing diverse properties which found application in medical science, mainly as drug delivery systems. The main objective of this paper was a preliminary evaluation of the chemical and phase structure of new polymeric materials capable to self-assembly in a solution. The chemical structure of the final product was characterized by ATR FTIR spectroscopy, the phase structure was estimated based on DSC analysis, the ability to create self-assembled micellar/nanospheric structures and the critical micelle concentration were characterized by UV-VIS spectroscopy. FTIR analysis confirmed that new poly(arylane-ester)s modified with polyethers of different molecular masses were obtained. DSC thermograms indicated the micro-phase separation of molecular structure for material modified with poly(ethylene glycol) (PEG) of 2000 g/mol. The critical micelle concentration for this material was 0.2%(w/v) as determined by spectroscopic technique. The obtained results are good promise for further modification of synthesized poly(arylane-ester) with other monomers (not only polyethers) to obtain materials with higher capacity to self-assembly into well-defined micells/nanospheres.

18

Fluvastatin increases tyrosinase synthesis induced by UVB irradiation of B16F10 melanoma cells

51%

Galus R. , Sajjad E. , Niderla J. , Borowska K. , Wlodarski K. , Wlodarski P. , Jozwiak J.

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2009

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tom 47

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nr 3

19

Ibuprofen-tyrosine (Val-Tyr, Val-Tyr-Val) interactions. Theoretical and experimental studies

51%

Kowalska-Baron A. , Brychtova M. , Petrovic I. , Passos Sene I. , Quinones P. , Sogorkova J.

Biotechnology and Food Science

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2011

|

tom 75

|

nr 2

20

Foliar treatment with proline and tyrosine affect the growth and yield of beetroot and some pigments in beetroot leaves

51%

El-Sherbeny M. R. , Teixeira da Silva J. A.

Journal of Horticultural Research

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2013

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tom 21

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nr 2