TY - JOUR
T1 - A GFET Nitrile Sensor Using a Graphene‐Binding Fusion Protein
AU - Mohamed, Abubaker Abdillahi
AU - Noguchi, Hironaga
AU - Tsukiiwa, Mirano
AU - Chen, Chen
AU - Heath, Rachel
AU - Bin Mubarak, Muhammad Qadri Effendy
AU - Komikawa, Takumi
AU - Tanaka, Masayoshi
AU - Okochi, Mina
AU - De Visser, Samuel
AU - Hayamizu, Yuhei
AU - Blanford, Christopher F.
PY - 2022/11/10
Y1 - 2022/11/10
N2 - A new route to single-step, non-covalent immobilization of proteins on graphene is exemplified with the first biosensor for nitriles based on a graphene field-effect transistor (GFET). The biological recognition element is a fusion protein consisting of nitrile reductase QueF from E. coli with an N-terminal self-assembling and graphene-binding dodecapeptide. Atomic force microscopy and analysis using a quartz crystal microbalance show that both the oligopeptide and the fusion protein incorporating it form a single adlayer of monomeric enzyme on graphene. The fusion protein has a 6.3-fold increase in binding affinity for benzyl cyanide (BnCN) versus wild-type QueF and a 1.4-fold increase for affinity for the enzyme’s natural substrate preQ0. Density functional theory analysis of QueF’s catalytic cycle with BnCN shows similar transition-state barriers to preQ0, but differences in the formation of the initial thioimidate covalent bond (ΔG‡ = 19.0 kcal mol–1 for preQ0 vs 27.7 kcal mol–1 for BnCN) and final disassociation step (ΔG = –24.3 kcal mol–1 for preQ0 vs ΔG = +4.6 kcal mol–1 for BnCN). Not only do these results offer a single-step route to GFET modification, but they also present new opportunities in the biocatalytic synthesis of primary amines from nitriles.
AB - A new route to single-step, non-covalent immobilization of proteins on graphene is exemplified with the first biosensor for nitriles based on a graphene field-effect transistor (GFET). The biological recognition element is a fusion protein consisting of nitrile reductase QueF from E. coli with an N-terminal self-assembling and graphene-binding dodecapeptide. Atomic force microscopy and analysis using a quartz crystal microbalance show that both the oligopeptide and the fusion protein incorporating it form a single adlayer of monomeric enzyme on graphene. The fusion protein has a 6.3-fold increase in binding affinity for benzyl cyanide (BnCN) versus wild-type QueF and a 1.4-fold increase for affinity for the enzyme’s natural substrate preQ0. Density functional theory analysis of QueF’s catalytic cycle with BnCN shows similar transition-state barriers to preQ0, but differences in the formation of the initial thioimidate covalent bond (ΔG‡ = 19.0 kcal mol–1 for preQ0 vs 27.7 kcal mol–1 for BnCN) and final disassociation step (ΔG = –24.3 kcal mol–1 for preQ0 vs ΔG = +4.6 kcal mol–1 for BnCN). Not only do these results offer a single-step route to GFET modification, but they also present new opportunities in the biocatalytic synthesis of primary amines from nitriles.
U2 - 10.1002/adfm.202207669
DO - 10.1002/adfm.202207669
M3 - Article
SN - 1616-3028
JO - Advanced Functional Materials
JF - Advanced Functional Materials
ER -