The partial characterization of the binding of avidin-biotin complex to rat liver plasma membrane.

Rat liver plasma membrane and rat intestinal mucosa plasma membrane were examined for their ability to bind avidin-[3H]biotin complex. Avidin-[3H]biotin complex bound specifically to liver plasma membrane with a Kd of approx. 35 nM and Bmax. of 136 pmol/mg of membrane protein. The receptor on the liver plasma membrane was exposed by Pronase, sensitive to tryptic hydrolysis and insensitive to neuraminidase. The optimum pH of specific binding was less than 6.0. Simple carbohydrates, mannan and ovalbumin did not inhibit specific binding. Periodate-treated or alpha-mannosidase-treated avidin was able to inhibit binding of either avidin-[3H]biotin complex or untreated avidin to plasma membrane. [3H]Avidin containing methylated lysine residues did not bind to rat liver plasma membrane. There was no specific binding of the avidin-biotin complex to rat intestinal mucosa plasma membrane.