Shedding of hyaluronate synthase from streptococci.
Hyaluronate synthase was shed into the culture medium from growing streptococci (group C) together with nascent hyaluronate. The mechanism of solubilization was analysed using isolated protoplast membranes. Solubilization increased when membranes were suspended in larger volumes, but it was temperature-independent and was not inhibited by protease inhibitors. Increased hyaluronate chain length enhanced solubilization. The soluble synthase could re-integrate into Streptococcal membranes in a saturable manner. The soluble synthase behaved like an integral membrane protein, although it was not integrated into phospholipid vesicles. In sucrose velocity centrifugation the synthase had a higher sedimentation rate in detergent-free solution, indicating that it existed in an aggregated state.
Mausolf
A
A
Max Planck Institut für Biochemie, Martinsried, Federal Republic of Germany.
Jungmann
J
J
Robenek
H
H
Prehm
P
P
D015153:Blotting, Western; D002462:Cell Membrane / Q000201:enzymology; D002499:Centrifugation, Density Gradient; D014453:Glucuronosyltransferase / Q000378:metabolism*; D016695:Glycosyltransferases; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000096:biosynthesis; D007700:Kinetics; D046911:Macromolecular Substances; D015636:Magnesium Chloride / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D012995:Solubility; D013291:Streptococcus / Q000201:enzymology*; D014166:Transferases; D014537:Uridine Diphosphate N-Acetylglucosamine / Q000494:pharmacology; D029867:Xenopus Proteins
D046911:Macromolecular Substances; D008565:Membrane Proteins; D029867:Xenopus Proteins; D015636:Magnesium Chloride; D014537:Uridine Diphosphate N-Acetylglucosamine; D006820:Hyaluronic Acid; D014166:Transferases; D016695:Glycosyltransferases; D014453:Glucuronosyltransferase; C056944:HAS1 protein, Xenopus; D000076002:Hyaluronan Synthases