Immunological comparison of biotinidase in serum from normal and biotinidase-deficient individuals

An antiserum specific to enzymatically active human serum biotinidase was prepared. Using this antiserum, two immunologically cross-reacting protein fractions, only one of which corresponds to the active enzyme, were observed in sera from individuals with normal biotinidase activity. Neither of these protein fractions was detected in sera from 18 individuals with biotinidase deficiency from 15 families.