Peroxisomal integral membrane proteins in livers of patients with Zellweger syndrome, infantile Refsum's disease and X‐linked adrenoleukodystrophy

Abstract

Livers from seven patients with peroxisome disorders, three with Zellweger syndrome, one with infantile Refsum's syndrome and three with X-linked adrenoleukodystrophy, were analysed by immunoblotting. The bifunctional protein catalysing two peroxisomal β-oxidation reactions was deficient in all Zellweger livers and in the infantile Refsum's liver, consistent with the absence of morphologically recognizable peroxisomes. Three peroxisomal integral membrane proteins (IMPs) (69, 53 and 22 kDa) were present in normal amounts in all the Zellweger and adrenoleukodystrophy samples and they sedimented in a membrane fraction. These membrane proteins were also present in the infantile Refsum's liver. We suggest, on the basis of these results, that aberrant peroxisomal membranes may be present in Zellweger syndrome and that the defect is in the transport of matrix proteins into the organelle.