2013
Cation-Specific Effects on Enzymatic Catalysis Driven by Interactions at the Tunnel Mouth.
ŠTĚPÁNKOVÁ, Veronika; J. PATEROVA; Jiří DAMBORSKÝ; P. JUNGWIRTH; Radka CHALOUPKOVÁ et al.Základní údaje
Originální název
Cation-Specific Effects on Enzymatic Catalysis Driven by Interactions at the Tunnel Mouth.
Autoři
ŠTĚPÁNKOVÁ, Veronika; J. PATEROVA; Jiří DAMBORSKÝ; P. JUNGWIRTH; Radka CHALOUPKOVÁ a J. HEYDA
Vydání
Journal of Physical Chemistry B, 2013, 1520-6106
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10600 1.6 Biological sciences
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 3.377
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/13:00066616
Organizační jednotka
Přírodovědecká fakulta
UT WoS
Klíčová slova anglicky
Tunnel Mouth; Interactions
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 29. 4. 2014 14:02, Ing. Zdeňka Rašková
Anotace
V originále
Cationic specificity which follows the Hofmeister series has been established for the catalytic efficiency of haloalkane dehalogenase LinB by a combination of molecular dynamics simulations and enzyme kinetic experiments. Simulations provided a detailed molecular picture of cation interactions with negatively charged residues on the protein surface, particularly at the tunnel mouth leading to the enzyme active site. On the basis of the binding affinities, cations were ordered as Na+ > K+ > Rb+ > Cs+. In agreement with this result, a steady-state kinetic analysis disclosed that the smaller alkali cations influence formation and productivity of enzyme–substrate complexes more efficiently than the larger ones. A subsequent systematic investigation of two LinB mutants with engineered charge in the cation-binding site revealed that the observed cation affinities are enhanced by increasing the number of negatively charged residues at the tunnel mouth, and vice versa, reduced by decreasing this number. However, the cation-specific effects are overwhelmed by strong electrostatic interactions in the former case. Interestingly, the substrate inhibition of the mutant LinB L177D in the presence of chloride salts was 7 times lower than that of LinB wild type in glycine buffer. Our work provides new insight into the mechanisms of specific cation effects on enzyme activity and suggests a potential strategy for suppression of substrate inhibition by the combination of protein and medium engineering.
Návaznosti
| GAP207/12/0775, projekt VaV |
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