Desorption and exchange properties of adsorbed albumin on apatite. Influence of long-term interfacial residence times.
A technique using 125I-labeled proteins was employed to study static adsorption properties and slow exchange and desorption processes of human albumin in contact with synthetic hydroxyapatite beads. With the aid of a thermostated "minicolumn," the adsorption isotherm was obtained during a so-called multiadsorption process, and could be described by a Langmuir adsorption model (K = 1.10 x 10(10) cm3.mol-1). All kinetic desorption and exchange experiments could be fitted by a simple exponential function of time. No influence of long-term interfacial residence times on characteristic relaxation times or percentage of desorbed or exchanged proteins could be detected in the present system. On the other hand, as compared to the low surface coverage domain, the small percentage of desorbable and high percentage of exchangeable molecules in the adsorption plateau domain was attributed to a bimolecular exchange process.
Mura
M J
MJ
CTR Odontologiques, U157 INSERM, Strasbourg, France.
Behr
S
S
Voegel
J C
JC
D000327:Adsorption; D000418:Albumins; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006801:Humans; D006882:Hydroxyapatites; D007457:Iodine Radioisotopes; D007474:Ion Exchange; D007700:Kinetics; D008863:Microspheres
D000418:Albumins; D006882:Hydroxyapatites; D007457:Iodine Radioisotopes