Effect of tin oxide nanoparticle binding on the structure and activity of α-amylase from Bacillus amyloliquefaciens.
Proteins adsorbed on nanoparticles (NPs) are being used in biotechnology, biosensors and drug delivery. However, understanding the effect of NPs on the structure of proteins is still in a nascent state. In the present paper tin oxide (SnO2) NPs were synthesized by the reaction of SnCl4·5H2O in methanol via the sol-gel method and characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The binding of these SnO2-NPs with α-amylase was investigated by using UV-vis, fluorescence and circular dichroism (CD) spectroscopic techniques. A strong quenching of tryptophan fluorescence intensity in α-amylase was observed due to formation of a ground state complex with SnO2-NPs. Far-UV CD spectra showed that the secondary structure of α-amylase was changed in the presence of NPs. The Michaelis-Menten constant (K(m)), was found to be 26.96 and 28.45 mg ml(-1), while V(max) was 4.173 and 3.116 mg ml(-1) min(-1) for free and NP-bound enzyme, respectively.
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh-202002, India.
Mohammad Jahir
MJ
Khan
Shariq
S
Qayyum
Fahad
F
Alam
Qayyum
Q
Husain
D000704:Analysis of Variance; D001407:Bacillus / Q000187:drug effects* / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D002942:Circular Dichroism; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D016014:Linear Models; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D017971:Tin Compounds / Q000494:pharmacology*; D014364:Tryptophan; D014961:X-Ray Diffraction; D000516:alpha-Amylases / Q000737:chemistry* / Q000378:metabolism
D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D017971:Tin Compounds; D014364:Tryptophan; D000516:alpha-Amylases; C045358:stannic oxide