Phospholipid bilayers deposited on sensor surfaces are excellent subst
rates for immobilizing proteins via a molecular anchor. An integrated
optics sensing device was used to accurately measure the binding kinet
ics of proteins thus anchored. By comparing the results with measureme
nts using proteins from which the anchor had been enzymatically remove
d, it was shown that the anchor accounts for essentially all the irrev
ersible binding. The insertion of the anchor into the lipid bilayer is
a spontaneous process. This method of immobilization should be widely
applicable to many soluble protein molecules, to which an anchor can
be attached by routine methods of molecular engineering.