title: Biomimicry enhances sequential reactions of tethered glycolytic enzymes, TPI and GAPDHS.
abstract: Maintaining activity of enzymes tethered to solid interfaces remains a major challenge in developing hybrid organic-inorganic devices. In nature, mammalian spermatozoa have overcome this design challenge by having glycolytic enzymes with specialized targeting domains that enable them to function while tethered to a cytoskeletal element. As a step toward designing a hybrid organic-inorganic ATP-generating system, we implemented a biomimetic site-specific immobilization strategy to tether two glycolytic enzymes representing different functional enzyme families: triose phosphoisomerase (TPI; an isomerase) and glyceraldehyde 3-phosphate dehydrogenase (GAPDHS; an oxidoreductase). We then evaluated the activities of these enzymes in comparison to when they were tethered via classical carboxyl-amine crosslinking. Both enzymes show similar surface binding regardless of immobilization method. Remarkably, specific activities for both enzymes were significantly higher when tethered using the biomimetic, site-specific immobilization approach. Using this biomimetic approach, we tethered both enzymes to a single surface and demonstrated their function in series in both forward and reverse directions. Again, the activities in series were significantly higher in both directions when the enzymes were coupled using this biomimetic approach versus carboxyl-amine binding. Our results suggest that biomimetic, site-specific immobilization can provide important functional advantages over chemically specific, but non-oriented attachment, an important strategic insight given the growing interest in recapitulating entire biological pathways on hybrid organic-inorganic devices.
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America.
authors.forename: Chinatsu
authors.initials: C
authors.lastname: Mukai
authors.forename: Lizeng
authors.initials: L
authors.lastname: Gao
authors.forename: Magnus
authors.initials: M
authors.lastname: Bergkvist
authors.forename: Jacquelyn L
authors.initials: JL
authors.lastname: Nelson
authors.forename: Meleana M
authors.initials: MM
authors.lastname: Hinchman
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Travis
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry* / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry; D057075:Enzyme Assays; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051379:Mice; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013737:Testis / Q000737:chemistry / Q000201:enzymology; D014305:Triose-Phosphate Isomerase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D011994:Recombinant Proteins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D014305:Triose-Phosphate Isomerase