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Biomedical subjects

R M Mason

Publications and source records attributed to R M Mason.

172 records · Page 10Linked to original sources
PubMedDate not supplied

Purification and properties of human placental cathepsin D.

Human placental cathepsin D has been purified 6000-fold and its properties characterized. Its molecular weight has been ascertained to be 42 000 by gel filtration and 43 300 by analytical ultracentrifugation. SDS gel electrophoresis in the presence of beta-mercaptoethanol cleaves the enzyme into two polypeptides of molecular weights 28 200 and 14 400. The placental enzyme resembles cathepsin D isolated from other mammalian tissues in many of its properties, including pH optimum. The higher degree of purification has led to a shift in the isoelectric points of the three isoenzymes from those recorded by other authors. Antibodies raised against cathepsin D in rabbits inhibit it at pH 5.0, and the inhibition is almost 100 per cent with adequate concentrations of monospecific antibody.

Antibodies↗
PubMedDate not supplied

Solubility of spinal ligament collagen in idiopathic and secondary scoliosis.

Supraspinous and interspinous ligaments from patients with infantile and adolescent idiopathic scoliosis and from patients with secondary scoliosis were investigated for collagen content and cross-linking. No differences were demonstrated in the collagen content of ligaments from the idiopathic and secondary scoliosis groups. Collagen solubility studies were used to test for cross-linking defects. Similar amounts of neutral salt-soluble and acetic acid-soluble collagen were extracted from the ligaments of all diagnostic groups. Investigation of the normally insoluble collagen pool extracted from the ligaments of different diagnostic groups after "lyotropic relaxation" revealed no differences in the amount of collagen extracted or in its stability to alkaline denaturation. Control experiments using rat skin collagen showed that the lyotropic procedure solubilized undegraded alpha- and beta-polypeptide chains from the tissue. Reports from other laboratories have suggested the presence of a collagen defect in the skin of patients with adolescent idiopathic scoliosis. The results of the present investigation show that it is unlikely that a generalized defect of collagen cross-linking, or a specific defect of ligament collagen cross-linking, occurs in either infantile or adolescent idiopathic scoliosis.

Adolescent↗