Peptides of the otosclerotic perilymph examined by analytical isotachophoresis.

Perilymphs of normal and otosclerotic origin were separated chromatographically on a Sephadex G-25 microcolumn. Peptide composition of the perilymphs was compared by capillary analytical isotachophoresis in the molecular mass range 0.3-5 kD. Otosclerotic perilymph samples contain a heterogeneous, UV-absorbing peptide subfraction which is not detected in the normal perilymph. Normal and otosclerotic perilymph, furthermore, contain four common subfractions detected in twice the normal concentration in the otosclerotic perilymph. These ITP subfractions are degraded during acid hydrolysis (6 M HCI). On the contrary, otosclerosis is a deficient state compared with the normal, as the number of peptides or oligoglycopeptides is twice as high in normal as in otosclerotic perilymph, beside the otosclerosis specific peptides.