Identification of a peanut agglutinin-binding protein from human retina

With the use of an antiserum raised to peanut agglutinin (PNA)-binding protein(s) from human retinas, we have identified a glycoprotein that has the same subunit molecular weight (135,000) as human interphotoreceptor retinol-binding protein (IRBP) on human retinal protein transblots, and, like IRBP, is localized in the interphotoreceptor matrix surrounding both rods and cones. We show that this PNA-binding protein is not IRBP by comparing the binding patterns of antiserum to the PNA-binding protein to binding patterns obtained with antisera to bovine and monkey IRBP.