Human retinol-binding protein (RBP) and prealbumin were labeled with Z-hydroxy&nitrobenzyl bromide (HNB-Br) at pH 5.5 using 20to loo-fold molar excess of the label over tryptophan in each protein. In prealbumin, only 1 to 1.7 tryptophan residues out of 8 were modified under these conditions. This modification did not alter the capacity of prealbumin to bind to retinol-RBP at physiological ionic...

Human retinol-binding protein (RBP) and prealbumin were labeled with Z-hydroxy&nitrobenzyl bromide (HNB-Br) at pH 5.5 using 20to loo-fold molar excess of the label over tryptophan in each protein. In prealbumin, only 1 to 1.7 tryptophan residues out of 8 were modified under these conditions. This modification did not alter the capacity of prealbumin to bind to retinol-RBP at physiological ionic...