Light- induced H2 generation in a photosystem I-O2-tolerant [FeFe] hydrogenase nanoconstruct

• 成果类型: Article
• 署名作者: Rumbaugh, Tristen D.; Gorka, Michael J.; Baker, Carol S.; Golbeck, John H.; Silakov, Alexey
• 署名单位: Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12079
• DOI: 10.1073/pnas.2400267121
• 发表日期: 2024-08-20
• 关键词: electron-transfer; photocatalytic production; oxygen; reduction; inactivation; nanoparticle; cluster; subunit; a(1a); h-2

摘要

The fusion of hydrogenases and photosynthetic reaction centers (RCs) has proven to be a promising strategy for the production of sustainable biofuels. Type I (iron- sulfur- containing) RCs, acting as photosensitizers, are capable of promoting electrons to a redox state that can be exploited by hydrogenases for the reduction of protons to dihydrogen (H2). While both [FeFe] and [NiFe] hydrogenases have been used successfully, they tend to be limited due to either O2 sensitivity, binding specificity, or H2 production rates. In this study, we fuse a peripheral (stromal) subunit of Photosystem I (PS I), PsaE, to an O2- tolerant [FeFe] hydrogenase from Clostridium beijerinckii using a flexible [GGS]4 linker group (CbHydA1- PsaE). We demonstrate that the Cb HydA1 chimera can be synthetically activated in vitro to show bidirectional activity and that it can be quantitatively bound to a PS I variant lacking the PsaE subunit. When illuminated in an anaerobic environment, the nanoconstruct generates H2 at a rate of 84.9 +/- 3.1 mu mol H2 mg chl-1 h-1. Further, when prepared and illuminated in the presence of O2, the nanoconstruct retains the ability to generate H2, though at a diminished rate of 2.2 +/- 0.5 mu mol H2 mg chl-1 h-1. This demonstrates not only that PsaE is a promising scaffold for PS I- based nanoconstructs, but the use of an O2- tolerant [FeFe] hydrogenase opens the possibility for an in vivo H2 generating system that can function in the presence of O2.