(95j) Reactivity of Hydrogen Sulfide with Hemeproteins Incorporated in Sol-Gel Matrices

Technology in sulfur compound biosensing can be developed by combining the sol-gel method with the properties of Hemoglobin I (HbI) from the clam Lucina pectinata. Hemoglobin I is the only one that takes an active role in H2S transport and transfer to intracellular chemoautotrophic symbiotic bacteria. Hemoglobin I can also bind other sulfur compounds, like CH3SH and (CH3)2S. Micro immobilization of HbI and Myoglobin (Mb) were performed in Tetramethylorthosilicate (TMOS) gels with no detrimental changes in the function of the proteins in solution. Sol-gel immobilization of HbI and Mb also increased the stability of the proteins and prevented denaturation due to changes in temperature, restricting the protein to the ferric oxidation state. Upon reaction of the encapsulated metaquo-HbI with H2S there is a change in the Soret band from 407 nm to 426 nm for HbI-SH2 complex. Identical spectra were obtained for both, buffer solution and sol-gel matrices. Similarly, the reaction of encapsulated metaquo-Mb shows a change in the in the Soret bands from 407 nm to 416 nm for Mb-N3 species. The results clearly demonstrate the ability of these proteins to retain the activity in sol-gel matrices.