Change of alpha-helical structure of heme protein (Hb) to a beta-sheet and random coil conformation because of the interaction of glycine capped gold nanoparticles (20-60 nm) as observed from attenuation total reflectance, absorption, Fourier transform infra red, and Circular Dichroism spectroscopy has been reported in this article. Upon interaction, protein takes a cylindrical shape of length 12 mu m and diameter 0.35 mu m as revealed from scanning electron microscopy and transmission electron microscopy. The Selected-Area Electron beam Diffraction pattern shows change of crystalline structure in GNP to amorphous nature with the interaction of Hb.