title: Extended and globular protein domains in cartilage proteoglycans.
abstract: Electron microscopy after rotary shadowing and negative staining of the large chondroitin sulphate proteoglycan from rat chondrosarcoma, bovine nasal cartilage and pig laryngeal cartilage demonstrated a unique multidomain structure for the protein core. A main characteristic is a pair of globular domains (diameter 6-8 nm), one of which forms the N-terminal hyaluronate-binding region. They are connected by a 25 nm-long rod-like domain of limited flexibility. This segment is continued by a 280 nm-long polypeptide strand containing most chondroitin sulphate chains (average length 40 nm) in a brush-like array and is terminated by a small C-terminal globular domain. The core protein showed a variable extent of degradation, including the loss of the C-terminal globular domain and sections of variable length of the chondroitin sulphate-bearing strand. The high abundance (30-50%) of the C-terminal domain in some extracted proteoglycan preparations indicated that this structure is present in the cartilage matrix rather than being a precursor-specific segment. It may contain the hepatolectin-like segment deduced from cDNA sequences corresponding to the 3'-end of protein core mRNA [Doege, Fernandez, Hassell, Sasaki & Yamada (1986) J. Biol. Chem. 261, 8108-8111; Sai, Tanaka, Kosher & Tanzer (1986) Proc. Natl. Acad. Sci. 83, 5081-5085; Oldberg, Antonsson & Heinegård (1987) Biochem. J. 243, 255-259].
authors: Abteilung Biophysikalische Chemie, Biozentrum, Basel, Switzerland.
authors: M
authors: M
authors: Paulsson
authors: M
authors: M
authors: Mörgelin
authors: H
authors: H
authors: Wiedemann
authors: M
authors: M
authors: Beardmore-Gray
authors: D
authors: D
authors: Dunham
authors: T
authors: T
authors: Hardingham
authors: D
authors: D
authors: Heinegård
authors: R
authors: R
authors: Timpl
authors: J
authors: J
authors: Engel
mesh_terms: D000818:Animals; D002356:Cartilage / Q000032:analysis*; D002813:Chondrosarcoma / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D008854:Microscopy, Electron; D011506:Proteins / Q000032:analysis; D011509:Proteoglycans
chemical_list: D011506:Proteins; D011509:Proteoglycans