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Wyszukujesz frazę "Kozłowski, H." wg kryterium: Autor


Wyświetlanie 1-2 z 2
Tytuł:
Polihistydylowe sekwencje z motywem His-tag – ich rola i biologiczne znaczenie oddziaływania z jonami metali
Polyhistidine sequences with His-tag motif – their role and biological significance of interaction with metal ions
Autorzy:
Wątły, J.
Kozłowski, H.
Powiązania:
https://bibliotekanauki.pl/articles/172145.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
histydyna
His-tag
jony metali
białka
histidine
His-tag motif
metal ions
proteins
Opis:
His-tags are specific sequences containing six to nine subsequent histydyl residues and they are used commercially in immobilized metal affinity chromatography (IMAC) as molecular ‘anchors’ that bind to a metal ion (usually nickel), immobilized by chelation with nitrilotriacetic acid (NTA) bound to a solid support [37, 38]. Consecutive histidines are the common denominator for both His-tags used in molecular biology and for quite remote biological phenomena – more than 2000 histidine- rich proteins (HRPs) are found in microorganisms including 60% and 82% of archaeal and bacterial species, respectively and their roles are not well characterized [73]. The physicochemical properties of histidine make it a versatile amino acid that influences protein conformation and enzymatic activity [15]. Many natural proteins with a His-tag domain are assigned to different functions, for example: most bacterial proteins, containing this motif are probably involved in the homeostasis of nickel ions [68, 76], while others, e.g. newly isolated peptides from the venom of the snake genus Atheris contain poly-histidyl-poly-glycyl sequences (pHpG) can act on the cardiovascular system by inhibiting snake venom metalloproteinases and affect its function by acting on specific receptors [58, 62]. His-rich motifs have been found also e.g. in Zn2+ transporters, prion proteins, His-rich glycoproteins, transcription factors or numerous copper-binding proteins [56, 67, 84]. Binding mode and the thermodynamic properties of the system depends on the specific metal ion and the histidine sequence. Despite the wide application of the His-tag for purification of proteins, little is known about the properties of metalbinding to such tag domain. Recent experimental and theoretical studies have shown that metal ions, e.g. Cu2+ can bind to various sets of imidazoles depending on the number of histidine residues that are located in His-rich sequences. The occurrence of polymorphic binding states and the formation of an α-helical structure induced by metal ion coordination suggest that proteins with a His-tag domain may serve as the dynamic site able to ‘move’ metal ions along the tag sequence [99, 100]. This might explain the frequent occurrence of such sequences in bacterial Ni2+ chaperones, which transfer the metal ion between different proteins.
Źródło:
Wiadomości Chemiczne; 2016, 70, 11-12; 1-24
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metalotioneiny i motywy policysteinylowe : oddziaływanie z jonami metali
Metallothioneins and polythiol motifs : interactions with metal ions
Autorzy:
Krzywoszyńska, K.
Kozłowski, H.
Powiązania:
https://bibliotekanauki.pl/articles/171939.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
metalotioneiny
motywy policysteinylowe
jony metali
metallothioneins
polythiol motifs
metal ions
Opis:
Many of biochemical paths and processes require some metal ions to occur. There are also known the negative effects of the presence of metal ions in the organism. The both sides of metal ions interactions on the living organism require specific regulations and cannot be left without supervision and control of the organism itself. One of the strategy to keep the control on metal ions are cystein-rich proteins that play crucial role in detoxication of metal ions that are dangerous for human organism as well as they help to maintain homeostasis of essential metal ions. Matallothioneins are one of the well known, but still not fully understood, cysteine- rich proteins. They are small proteins but may contain up to 30% of cysteine residues in the sequence, and what makes them very special from chemical point of view - all of the thiols present there are reduced [1]. This property makes these proteins very tempting for coordination of various metal ions. The most efficient binding to metallothionein is observed for the ions belonging to a Group 11 and 12. Cu+, Zn2+ and Cd2+ represent these metal ions [2]. Besides of the lack of disulfide bridges, metallothioneins show also the absence or low amount of aromatic amino acid residues in the sequence [1]. Studies of the metallothioneins and their isoforms among different organisms show that the position of cysteine residues is very conservative [3]. Considering this aspect of metallothionein structure, some specific motifs of cysteine residues arrangement can be found in the sequence of these proteins. Most of the common polythiol motifs are CXC, CXXC, CXXXC, CC – where C is a cysteine residue and X is random α-amino acid residue (other than cysteine) [3–5]. The influence of the cysteine residues organization on the specificity of metal ions binding was intensively studied. The differences observed for specificity of metal ions binding by metallothioneins and selected polythiol motifs are reviewed in this paper – with strong emphasis on the effect of the cysteine residues topography.
Źródło:
Wiadomości Chemiczne; 2018, 72, 7-8; 383-395
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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