Jump to main content
Jump to site search

Issue 77, 2017, Issue in Progress
Previous Article Next Article

Activity and stability analysis of covalent conjugated lysozyme-single walled carbon nanotubes: potential biomedical and industrial applications

Author affiliations

Abstract

Conjugated protein–carbon nanotubes possess unique physicochemical properties that make them attractive to a wide range of applications. We explored the effects of covalent conjugation of lysozymes with single-walled carbon nanotubes (SWCNTs) on its activity and stability. Lysozyme was conjugated onto carboxyl-functionalized SWCNTs through carbodiimide method. Post conjugation changes of the enzyme were investigated using fluorescence measurements to generate plots of protein unfolding at 0 and 6 M guanidine hydrochloride (Gn-HCl) concentrations. Free lysozyme showed a remarkable increase in the fluorescence intensity at 287 nm in addition to a red shift from 343 to 352 nm. The emission spectrum of conjugated lysozyme showed a significant increase in the fluorescence intensity at 287 nm and a significant decrease in intensity at 348 nm. These results confirmed that both tryptophan and phenylalanine residues have an important role in the fluorescence bulk of both free and conjugated lysozymes. Kinetic parameters of free and conjugated lysozyme activities (KM and Vmax), optimum pH, thermal and pH stability, and stability in the presence of denaturant agents such as urea and salts were investigated. Changes were observed in KM and Vmax from 4.8 to 5.6 mM and 193 to 197 nmol min−1, respectively. Conjugated lysozyme showed a remarkable increase in pH stability in a range of 3.0 to 10.0 at 70 °C. The results showed first-order inactivation kinetics for both forms of lysozyme with a rate constant of about 0.139 min−1 for 10 minutes of incubation at 70 °C in the presence of KCl and KSCN.

Graphical abstract: Activity and stability analysis of covalent conjugated lysozyme-single walled carbon nanotubes: potential biomedical and industrial applications

Back to tab navigation

Publication details

The article was received on 29 Jun 2017, accepted on 10 Oct 2017 and first published on 17 Oct 2017


Article type: Paper
DOI: 10.1039/C7RA07189B
Citation: RSC Adv., 2017,7, 48692-48701
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Activity and stability analysis of covalent conjugated lysozyme-single walled carbon nanotubes: potential biomedical and industrial applications

    Z. Borzooeian, M. E. Taslim, G. Borzooeian, O. Ghasemi and M. Aminlari, RSC Adv., 2017, 7, 48692
    DOI: 10.1039/C7RA07189B

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements