S-Layer protein from Lysinibacillus sphaericus JG-A12 as matrix for Au-III sorption and Au-nanoparticle formation
Jankowski, U; Merroun, ML; Selenska-Pobell, S; Fahmy, K
| HERO ID | 1438587 |
|---|---|
| In Press | No |
| Year | 2010 |
| Title | S-Layer protein from Lysinibacillus sphaericus JG-A12 as matrix for Au-III sorption and Au-nanoparticle formation |
| Authors | Jankowski, U; Merroun, ML; Selenska-Pobell, S; Fahmy, K |
| Journal | Spectroscopy |
| Volume | 24 |
| Issue | 1-2 |
| Page Numbers | 177-181 |
| Abstract | The strain Lysinibacillus sphaericus JG-A12, isolated from the uranium mining site at Haberland. Saxony (Germany) selectively and reversibly accumulates radionuclides and toxic metals. Metal binding occurs to its surface layer (S-layer) surrounding the cells. Here, we have studied by Fourier-transform infrared (FTIR) spectroscopy the protein structure and stability as a function of Au-III binding and the subsequent reductively induced formation of Au-nanoclusters. Similar to previously studied complexes with Pd-II. Au-treated S- layers become resistant to acid denaturation evidenced by little response of their amide I absorption frequency. However, the strong effect of Pd-II on the side chain carboxylate IR absorption intensity is not observed with gold. Particularly after reduction, the carboxyl absorption responds little to acidification and a fraction appears to be protonated already at neutral pH. We ascribe this to a hydrophobic environment of the carboxyl groups after formation of Au-nanoclusters. EXAFS spectra agree with the metallic Au-Au distance but the reduced coordination number indicates that the Au-nanoclusters do not exceed similar to 2 nm. Thus, the S-layer of L. sphaericus JG-A12 provides a biotemplate for efficient Au-nanocluster formation in an acid-resistant matrix and independently of cysteins. |
| Doi | 10.3233/SPE-2010-0408 |
| Wosid | WOS:000278029800026 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Source: Web of Science WOS:000278029800026 |
| Is Public | Yes |
| Keyword | Bioremediation; biotemplate; heavy metal binding; infrared spectroscopy; X-ray absorption |