Home List of Titles Hybrid biomaterials: surface-MALDI mass spectrometry analysis of covalent binding versus physisorption of proteins
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/58210
- Hybrid biomaterials: surface-MALDI mass spectrometry analysis of covalent binding versus physisorption of proteins
- McLean, Keith M.; McArthur, Sally L.; Chatelier, Ronald C.; Kingshott, Peter; Griesser, Hans J.
- Lysozyme, lactoferrin, trypsin and myoglobin were bound onto thin carboxymethyl-dextran coatings in two ways: by physisorption, and by an intended carbodiimide interfacial linking reaction. XPS analyses recorded substantial protein loadings on all the samples. In some cases, the protein coverages achieved by physisorption were larger than on covalent binding, indicating substantial affinity of the proteins for spontaneous adsorption onto the coatings. The observation of significant physisorption raised the question of to what extent physisorption competed with covalent binding when the intended covalent linking reaction was performed. The technique of Surface-MALDI mass spectrometry was found to be rapid, convenient, sensitive, and eminently suitable for probing for the presence of a physisorbed population among the covalently linked proteins. Control experiments with physisorbed samples showed that all the four proteins investigated gave rise to strong signals. On samples produced using carbodiimide linking, however, no protein signals were detected while photomatrix signals attested to successful evaporation of the matrix. Covalently linked proteins evidently were immune to desorption and detection by Surface-MALDI-MS. Using signal-to- noise ratios of spectra recorded on samples with approximate monolayer coverage of physisorbed proteins, it was estimated that a signal should have been detectable if, among the covalently coupled protein molecules, >1-2% of the total protein coverage present after intended covalent immobilization were physisorbed. Therefore, Surface-MALDI analyses suggest that within experimental accuracy, the carbodiimide chemistry used led to complete covalent interfacial immobilization of all four protein layers.
- Publication type
- Journal article
- Colloids and Surfaces B: Biointerfaces, Vol. 17, no. 1 (Jan 2000), pp. 23-35
- Publication year
- FOR Code(s)
- 0306 Physical Chemistry (Incl. Structural)
- Adsorption; Biomaterials; Covalent binding; Dextrin; Lactoferrin; Lysozyme; MALDI mass spectrometry; Mass spectrometry; Matrix assisted laser desorption ionization time of flight mass spectrometry; Molecular interaction; Myoglobin; Protein adsorption; Protein binding; Protein immobilisation; Trypsin; XPS; X ray photoelectron spectroscopy
- Publisher URL
- Copyright © 2000 Elsevier Science B.V. All rights reserved.
- Additional information
- This work was partially supported by the Commonwealth Government under the Cooperative Research Centres Scheme (Cooperative Research Centre for Eye Research and Technology), by Australian Postgraduate Research Awards and by the Ciba Vision Corporation (Atlanta, Georgia, United States).
- Peer reviewed