The rational design of a novel biocatalyst using the heme-nitric oxide/oxygen binding protein için kapak resmi
The rational design of a novel biocatalyst using the heme-nitric oxide/oxygen binding protein
Başlık:
The rational design of a novel biocatalyst using the heme-nitric oxide/oxygen binding protein
Yazar:
Aggrey-Fynn, Joana Efua, author.
Fiziksel Tanımlama:
xi, 63 leaves: illustrarions, charts;+ 1 computer laser optical disc
Özet:
Recent advances in recombinant DNA technology and protein design have led to the application of biocatalysis as an alternative to chemical catalysis in the synthesis of enantiopure products due to high regio- and enantioselectivity. Hemeproteins are proteins with a heme prosthetic group that play diverse roles in biological systems, making them good candidates for biocatalysis. The Heme-nitric oxide/oxygen binding (H-NOX) protein was identified by homology to the soluble guanylate cyclases. Here, the H-NOX domain from the methyl-accepting chemotaxis protein, Thermoanaerobacter tencogenesis (TtH-NOX), was tuned into a biocatalyst using rational design. Four variants of TtH-NOX were cloned, purified and characterized. Each variant was then tested for their catalase and peroxidase activities. The wild type TtH-NOX inefficiently catalyzed the hydrogen peroxide decomposition (catalase activity) and 2,2’-azino-bis(3- ethylbenzthiazoline-6-sulfonic acid (ABTS) oxidation (peroxidase activity). However, the Y140H mutant exhibited an efficient five-fold increase in catalase and peroxidase activities as compared to the wild type. The other mutants, H102Y, H102C and Y140A TtH-NOX, were not good catalysts for both reactions. Therefore, the mutations resulted in changes in reaction rates and electronic properties of the heme group. The mutations affected the molecular mechanism of the hemeprotein, showing that both the proximal and distal pocket residues are vital for catalysis. However, the mutation of the distal tyrosine to histidine of TtH-NOX has significantly improved its catalytic activities. These observations contribute to the understanding of the physiological roles of hemeproteins. This project could also lead to discovery of novel biocatalysts and aid in the design of future biocatalysts.
Yazar Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology: Molecular Biology and Genetics.

İzmir Institute of Technology: Molecular Biology and Genetics--Thesis (Master).
Elektronik Erişim:
Access to Electronic Versiyon.
Ayırtma: Copies: