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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Biochemical and biophysical characterization of lysozyme modified by PEGylation

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Author(s):
Freitas, Debora da Silva [1] ; Abrahao-Neto, Jose [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Sch Pharmaceut Sci, Dept Pharmaceut Technol & Biochem, BR-05508000 Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: International Journal of Pharmaceutics; v. 392, n. 1-2, p. 111-117, JUN 15 2010.
Web of Science Citations: 43
Abstract

PEGylation is a strategy that has been used to improve the biochemical properties of proteins and their physical and thermal stabilities. In this study, hen egg-white lysozyme (EC 3.2.1.17; LZ) was modified with methoxypolyethylene glycol-p-nitrophenyl carbonate (mPEG-pNP, MW 5000). This PEGylation of LZ produced conjugates that retained full enzyme activity with glycol chitosan, independent of degree of enzyme modification; its biological activity with the substrate Micrococcus lysodeikticus was altered according to its degree of modification. The conjugate obtained with a low degree of mPEG-pNP/NH(2) modification was studied by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), demonstrating a spectral peak at m/z 19,988 Da with 77% of its original enzymatic activity. Spectroscopic studies of Fourier transform infrared (FIR) and circular dichroism (CD) did not show any relevant differences in protein structure between the native and conjugate LZ. Studies of the effects of pH and temperature on PEGylated LZ indicated that the conjugate was active over a broad pH range, stable at 50 degrees C, and demonstrated resistance to proteolytic degradation. (C) 2010 Elsevier B.V. All rights reserved. (AU)