The discovery of novel dye-linked dehydrogenases in hyoerthermophiles and their application for biosensor elements

在嗜温微生物中发现了许多类型的染料连接的脱氢酶（dye-DH），并认为它们有可能用作生物传感器中的特异性元件。然而，它们的不稳定性限制了中温染料DHs的实际应用。另一方面，已知超嗜热菌产生高度稳定的染料-DH。它们的高稳定性使它们更适合于实际应用。本研究以基因组信息为基础，在超嗜热菌中发现了新的D-苯丙氨酸脱氢酶、三种类型的D-乳酸脱氢酶和L-脯氨酸脱氢酶（LPDH）。我们揭示了这些酶的酶学性质。此外，我们成功地进行了LPDH的晶体结构分析。最后，我们用超嗜热染料DHs构建了酶固定化电极，并证实这些电极可用于稳定的生物传感器。

Many types of dye-linked dehydrogenases(dye-DHs)have been identified in mesophilic microorganisms, and it has been suggested that they have the potential for use as specific elements in biosensors. However, their instability has limited the practical application of mesophilic dye-DHs. On the other hand, hyperthermophiles are known to produce highly stable dye-DHs. Their high stability make them more amenable to practical application. In this study, on the basis of genome information, we observed novel D-phenylalanine dehydrogenase, three types of D-lactate dehydrogenase, and L-proline dehydrogenase (LPDH) in hyperthermophiles. We revealed enzymological properties of these enzymes. Moreover, we succeeded in the crystal structure analysis of LPDH. Finally, we constructed enzyme-immobilized electrodes with hyperthermophilic dye-DHs and confirmed that these electrodes are available for stable biosensors.