We have prepared bio-inorganic nanohybrids consisting of magnetic inorganic nanolayers (iron-titanate) and protein molecules via exfoliation–restacking process in solution. It was found that the protein molecules were electrostatically and spontaneously incorporated into the interlayer space of the inorganic layered structure by adjusting the pH of the solution appropriately. The binding studies demonstrated the high affinity of the iron–titanate nanolayers for the proteins, and the immobilized protein preserved its activity after the hybridization. The catalytic activity measurement and magnetic separation experiment indicate the formation of magnetically applicable inorganic layer–biomolecule nanohybrids. The magnetic layer–biomolecule nanohybrid developed here would be a novel conspicuous material which shows different properties from those of conventional biomolecule-immobilized magnetic particles.