Preparation of a specific antiserum towards the microfibrillar protein of elastic tissues.

The microfibrillar protein (MFP) of bovine foetal ligamentum nuchae was prepared and used to induce an antiserum (I) in rabbit. Antibody (I), reacted with a dispersion of MFP in Ouchterlony plates, produced one major precipitin band (A) and two minor bands (B and C). The major band (A) was used to prepare antiserum (II) in a second rabbit. Antibody (II) was monospecific for precipitin band (A) and was shown to be selectively directed against MFP of bovine and chick elastic fibres by immunofluorescent and immunoperoxidase techniques. Immunoperoxidase-labelling techniques demonstrated the regular organization of microfibrillar protein on the surface of elastic fibres and suggested the ability of MFP to assemble into a framework defining the three dimensional polymerization of elastin monomers during the formation of elastin fibres. It was observed that collagen fibrils, which were in close association with the microfibrillar protein on the surface of elastic fibres, also possessed a protein which was immunologically related to MFP.