Summary
Blood coagulation factors XI and XIa possess binding site(s) for glass and plastics,
located in the heavy chain of the molecule. To elucidate the nature of binding, adsorption
and desorption properties of factor XI and XIa to different surfaces have been studied.
Desorption experiments with high salt (2.4 M NaCl) suggest participation of ionic
forces in the binding to glass. This is consistent with the decreased adsorption of
factor XI (pI – 9.0) to glass with increasing pH. The non-ionic detergent Triton X-100,
which splits hydrophobic bonds, desorbs factor XI very well from plastics and partially
from glass. The anionic detergent SDS, which will split hydrophobic as well as ionic
bonds, is the most effective agent tested for the elution of factor XI from glass.
We, therefore infer, that the binding of factor XI to glass is the combined effect
of ionic and hydrophobic binding, whereas the adsorption of factor XI to plastics
is primarily hydrophobic.
Key words
Surface adsorption of factor XI
