title: Cell-surface collagen-binding protein in the procaryote Achromobacter iophagus.
abstract: Collagen and its high-molecular-weight fragments specifically induce an extracellular collagenase (EC 3.4.24.8) in the Gram-negative Achromobacter iophagus. During the induction process the inducer is concentrated on the bacterial outer membrane. Two-dimensional electrophoresis of 125I-labelled outer membrane proteins has shown that, in particular, the amount of one protein which is already present on the surface of non-induced bacteria increases quantitatively when the inducer is added. After 125I-labelling of the cell membrane and its solubilization, the same protein is retained selectively on a gelatin-Sepharose column. It has isoelectric point of 4.9-5.1 and molecular weight of 40000. This molecular weight is close to that of the 35000 of the collagenase subunit. However, their non-identity was proved in three independent ways: upon two-dimensional electrophoresis, only those proteins in the range corresponding to the collagenase dimer (Mr 70000-80000) react with fluorescent anticollagenase antibody system, whereas the spot of the collagen-binding protein (mr 40000) is negative; the solubilized collagen-binding protein is not retained by anticollagenase-Sepharose affinity chromatography; in vivo, it is not protected by anti-collagenase antibodies against lactoperoxidase iodination. A hypothesis for the possible role of the collagen-binding protein in the induction of collagenase is proposed.
mesh_terms: D000421:Alcaligenes / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002846:Chromatography, Affinity; D003094:Collagen / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D013104:Spheroplasts / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D003094:Collagen