Quantification of Hen Egg White Lysozyme in Cartilage by an Enzyme-Linked Immunosorbent Assay

We have developed an enzyme-linked immunosorbent assay (ELISA) with an inhibition step to quantify hen egg white lysozyme (HEWL) on a weight basis. The assay is relatively insensitive to changes in ionic strength or pH. Quantification is not affected by the presence or large amounts of mammalian lysozymes or inhibitors of enzymatic activity such as soluble chitin oligomers. We used this ELISA to show that the HEWL content of chick cartilages increases progressively between days 14 and 18 of embryonic life. The maturation-related increase does not appear to be the result of increased synthesis by the chondrocytes for the latter did not synthesize detectable amounts of lysozyme in vitro. Evidence was obtained to suggest that most, if not all, the lysozyme in cartilage is derived from the surrounding fluids which come in contact with the matrix.