title: Adsorption and desorption of lysozyme on nano-sized magnetic particles and its conformational changes.
abstract: Adsorption and desorption of lysozyme on nano-sized magnetic particles and its conformational change were studied in this work. Adsorption of lysozyme on nano-sized magnetic particles (Fe(3)O(4)) was carried out at different pH. Maximum adsorption of lysozyme (4.65 mg/m2) occurred at its isoelectric point (pI = 11.1). Differential scanning calorimetry (DSC) results show that the lysozyme adsorbed on magnetic particles did not show any thermal transition over the range 20-100 degrees C. High desorption of lysozyme from magnetic particles was achieved using NaH(2)PO(4) (pH 4.0) (90%) and NaSCN (pH 6.0) (97%) as desorbents. The conformational change of the lysozyme desorbed by NaH(2)PO(4) was small, while the lysozyme desorbed by NaSCN underwent a significant conformational change as measured by the intrinsic fluorescence. Eighty-eight and 82% activity was retained in the desorbed enzyme for desorption by NaH(2)PO(4) and NaSCN, respectively.
authors.affiliation: Department of Chemical and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore.
authors.forename: Z G
authors.initials: ZG
authors.lastname: Peng
authors.forename: K
authors.initials: K
authors.lastname: Hidajat
authors.forename: M S
authors.initials: MS
authors.lastname: Uddin
mesh_terms: D000327:Adsorption; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D008280:Magnetics; D009113:Muramidase / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology*; D010316:Particle Size; D010710:Phosphates / Q000494:pharmacology; D011487:Protein Conformation / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013861:Thiocyanates / Q000494:pharmacology
chemical_list: D010710:Phosphates; D013861:Thiocyanates; C024553:sodium thiocyanate; D009113:Muramidase; C018279:sodium phosphate