Glomerular basement membrane antigens of Masugi nephritis.

Abstract

Glomerular basement membrane (GBM) isolated from rat, dog and human kidneys were treated with enzymes to obtain soluble membrane preparations. Gel filtration on calibrated columns of soluble membrane preparations produced several macromolecules which were identified as glycoproteins and glycopeptides, depending on their molecular sizes. A sialoglycoprotein of 50,000 Daltons is shown to be the nephrotoxigenic antigen of the GBM. Lipids were shown to be a non-essential component of the nephrotoxigenic antigen. Collagen and several other glycopeptides were found to be non-nephrotoxigenic antigens of the GBM. Use of pronase or combinations of certain enzymes (for example, collagenase and pronase, pepsin and trypsin) to obtain the soluble components of the membrane led to an alteration of the nephrotoxigenic antigen molecule.