Hemoglobin I from Lucina Pectinata Microinmobilized into Tetramethylorthosilicate Matrix Interacting with Metaquo-Mbsh2 Solution

Hemoglobin I (HbI) from the bivalve mollusk Lucina pectinata provides special properties that, combined with technology in sulfur compound biosensig, make the development of a sol-gel matrix to encapsulate the hemeproteins our current field of study. HbI is the only protein from this clam that takes an active role in H2S transport and transfer to intracellular chemoautotrophic symbiotic bacteria. Microimmobilization of HbI was performed in Tetramethylorthosilicate (TMOS) gels with no detrimental changes in the function of these proteins in solution. Intramuscular horse Mioglobin (Mb) was utilized as a model of HbI to protocols development. An increment in the stabilization and the prevention from temperature denaturation of proteins had been observed when inmobilized in sol-gels; the encapsulated protein is restricted to the ferric oxidation state (Fe3+) within the sol-gel matrix. Encapsulated protein shows a change in the Soret bands from 407 nm to 416 nm when subjected to H2S; these results clearly demonstrate the ability of these proteins to retain the activity. Kinetic studies were performed in order to determine both kon and koff; also a comparison between such values and the ones obtained when having the protein into solution was done. Encapsulated HbI was submerged into metaquo-Mb/H2S complex; kinetics measurements enable us to follow the H2S migration indicating the relative affinities of both proteins to H2S.