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Photosensitized reduction of water to hydrogen using human serum albumin complexed with zinc-protoporphyrin IX.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Komatsu, Teruyuki Wang, Rong-Min Zunszain, Patricia A. Curry, Stephen Tsuchida, Eishun |
| Copyright Year | 2006 |
| Abstract | We present the photophysical properties of complexes of recombinant human serum albumin (rHSA) with Zn(II)-protoporphyrin IX (ZnPP) and their activities in the photosensitized reduction of water to hydrogen (H2) using methyl viologen (MV2+) as an electron relay. The ZnPP is bound in subdomain IB of wild-type rHSA [rHSA(wt] by an axial coordination of Tyr-161 and, in the rHSA(I142H/Y161L) mutant [rHSA(His], by a His-142 coordination. Both the rHSA(wt)-ZnPP and rHSA(His)-ZnPP complexes showed a long-lived photoexcited triplet state with lifetimes (tauT) of 11 and 2.5 ms, respectively. The accommodation of ZnPP into the protein matrix efficiently eliminated the collisional triplet self-quenching process. The addition of a water-soluble electron acceptor, MV2+, resulted in a significant decrease in the triplet lifetime. The transition absorption spectrum revealed the oxidative quenching of rHSA-3ZnPP* by MV2+. The quenching rate constant (kq) and backward electron transfer rate constant (kb) were determined to be 1.4 x 10(7) and 4.7 x 10(8) M(-1) s(-1) for rHSA(wt)-ZnPP. In the presence of the colloidal PVA-Pt as a catalyst and triethanolamine (TEOA) as a sacrificial electron donor, the photosensitized reduction of water to H2 takes place. The efficiency of the photoproduction of H2 was greater than that of the system using the well-known organic chromophore, tetrakis(1-methylpyridinium-4-yl)porphinatozinc(II) (ZnTMPyP4+), under the same conditions. |
| File Format | PDF HTM / HTML |
| DOI | 10.1021/ja0656806 |
| PubMed reference number | 17165784 |
| Journal | Medline |
| Volume Number | 128 |
| Issue Number | 50 |
| Alternate Webpage(s) | http://www.canli.dicp.ac.cn/Gruop%20Seminars%20Pdf/200708JiaGQ.pdf |
| Alternate Webpage(s) | http://canli.dicp.ac.cn/Gruop%20Seminars%20Pdf/200708JiaGQ-SI.pdf |
| Journal | Journal of the American Chemical Society |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
