Determination of protein content in aqueous humour by high-performance gel filtration chromatography

High-performance liquid chromatography (HPLC) was used to study the protein content of aqueous humour in 17 cataract patients. High-performance gel filtration chromatograms (HPGFC) of the aqueous humour showed 7-12 peaks with low concentrations (mean 0.085 micrograms/microliter) of high molecular weight proteins (peak 1, MW 250 000 or more) and low levels (0.01 micrograms/microliter or less) of IgA (peak 2) and of IgG (peak 3). The fourth peak (MW about 65 000) containing albumin and obviously also trasferrin was the major peak (mean 0.596 micrograms/microliter) at HPGFC of a normal aqueous humour. Lysozyme (peak 6, MW 35 000) occurred in small amounts in the aqueous humour (mean 0.064 micrograms/microliter). The last 6 peaks matched for peptides and amino acids (MW 10 000 or less). It is concluded that HPLC may be a useful preparative method in characterization, separation, and partial purification of immunoglobulins, immune complexes, and other proteins of aqueous humour.