Premium
Adsorption of fluorescein by protein crystals
Author(s) -
Cvetkovic A.,
Zomerdijk M.,
Straathof A.J.J.,
Krishna R.,
van der Wielen L.A.M.
Publication year - 2004
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20167
Subject(s) - lysozyme , adsorption , fluorescein , chemistry , langmuir adsorption model , langmuir , crystallography , crystal (programming language) , protein adsorption , chromatography , fluorescence , organic chemistry , biochemistry , optics , physics , computer science , programming language
Adsorption characteristics of native and cross‐linked lysozyme crystals were examined using fluorescein as model adsorbate. The adsorption isotherms exhibited Langmuir or linear behavior. The affinity constant ( b 1 ) and the adsorption capacity ( Q sat ) for fluorescein were found to depend on the type and concentration of co‐solute present in the solution. The dynamics of adsorption isotherm transition from Langmuir to linear showed that affinity of lysozyme for solutes increases in the order 2‐(cyclohexylamino)ethanesulphonic acid (CHES), 4‐morpholinepropanesulphonic acid (MOPS), acetate, fluorescein. Furthermore, the crystal morphology, the degree of cross‐linking of the crystals, and, in particular, solution pH were identified as factors determining fluorescein adsorption by the lysozyme crystals. These factors seem to affect crystal capacity for the solute more than affinity for the solute. Adsorption of fluorescein by cross‐linked tetragonal lysozyme crystals was exponentially dependent on the lysozyme net charge calculated from the final solution pH. The 3–5‐fold increase in the fluorescein adsorption as a result of cross‐linking is presumably due to the increasing hydrophobicity of the lysozyme crystal. © 2004 Wiley Periodicals, Inc.