ABSTRACT
The actions of biosignal molecules, such as hormones, cell growth factors, cell differentiation factors, and neurotransmitters, are initiated through a complex formation with their receptors. The biospecific interaction between the immobilized insulin and its receptor was demonstrated by the fact that preadsorption of the anti-insulin antibody specifically suppressed the enhancement of cell growth. The action mechanism of transferrin was also revealed by this immobilization method. The immobilized transferrin not only transported Fe ion into cells, but also enhanced cell growth. The immobilization or insolubilization method is very useful for investigating signal transduction mechanisms. Other methods have been designed to reveal the biosignaling mechanisms. The effects of immobilized biosignal molecules are considered to be divided as follows, multivalent simultaneous activation, promotion of cross-linking, suppression of down-regulation, and perturbation of lipid cell membranes.
