title: Binding studies of hydroxylated Multi-Walled Carbon Nanotubes to hemoglobin, gamma globulin and transferrin.
abstract: Biocompatibility of nanoparticles depends on their binding behavior with biomolecules. Herein, we have reported the interaction of three different biological macromolecules such as hemoglobin, gamma globulin and transferrin with hydroxyl group functionalized Multi-Walled Carbon Nanotubes (OH-MWCNTs). Multiple spectroscopic methods were utilized to identify the binding cum structural changes in biomolecules upon their interaction. Hyperchromic effect observed in the UV-visible spectra, and the quenching behavior from fluorescence emission evidences the existence of bio-nanotube complex formation. Synchronous and three-dimensional fluorescence spectra of biomolecules, in correspondence with Trp and Tyr residues showed the possible disturbance towards their aromatic micro-environment. Changes observed in the FTIR and FT-Raman amide bands, and amino acid residue position of biomolecules upon interaction with CNTs showed the possible effect towards their secondary structure. Further studies with CD spectroscopy indicated the loss of alpha-helical structures quantitatively. The study remains significant in evaluating the biosafety profile of functionalized MWCNTs for their in vivo biomedical applications.
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore 632014, Tamil Nadu, India.
authors.forename: Gajalakshmi
authors.initials: G
authors.lastname: Sekar
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore 632014, Tamil Nadu, India.
authors.forename: Shirona Thazae
authors.initials: ST
authors.lastname: Kandiyil
authors.affiliation: School of Advanced Sciences, VIT University, Vellore 632014, Tamil Nadu, India.
authors.forename: Amaravathy
authors.initials: A
authors.lastname: Sivakumar
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore 632014, Tamil Nadu, India.
authors.forename: Amitava
authors.initials: A
authors.lastname: Mukherjee
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore 632014, Tamil Nadu, India. Electronic address: nchandra40@hotmail.com.
authors.forename: Natarajan
authors.initials: N
authors.lastname: Chandrasekaran
mesh_terms: D002942:Circular Dichroism; D006454:Hemoglobins / Q000737:chemistry / Q000378:metabolism*; D006900:Hydroxylation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D014168:Transferrin / Q000737:chemistry / Q000378:metabolism*; D005719:gamma-Globulins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D006454:Hemoglobins; D037742:Nanotubes, Carbon; D014168:Transferrin; D005719:gamma-Globulins
keywords: Alpha-helix; Amide bands; Conformation; Macromolecules; Quenching