초록
<P>The association of formaldehyde dehydrogenase from <I>Pseudomonas putida</I> (FalDH) with two different magnetic nanoparticles led to distinct enzyme responses depending upon the chemical modification process applied. The magnetite nanoparticles coated with aminopropyltriethoxysilane (MagNP-APTS) exhibited a lower activity and stability, while magnetite coated with a silica shell and APTS (MagNP@SiO<SUB>2</SUB>APTS) afforded excellent results, improving the stability and performance of FalDH in relation to the free enzyme. Such differences were ascribed to unfavorable conformational changes in the MagNP-APTS–FalDH system, as indicated by the kinetics and Raman spectroscopy data, not discarding the possible interference from the exposed Fe(<SMALL>II</SMALL>)/(<SMALL>III</SMALL>) ions. The MagNP@SiO<SUB>2</SUB>APTS–FalDH catalyst could be successfully recycled by using an external magnet, keeping its highest performance close to 100%, during the first four cycles, and decaying slightly up to 70% after the 10th cycle.</P><BR><BR><P>Graphic Abstract</P><P>The association of formaldehyde dehydrogenase from <I>Pseudomonas putida</I> (FalDH) with two different magnetic nanoparticles led to distinct enzyme responses depending upon the chemical modification process applied.<BR><IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4nj01716a'><BR></P>