Biomaterial Database

Trypsin-uncoupled synthesis and secretion of yeast invertase: implications for the mechanism of secretion. 1979

B E Holbein, and D K Kidby

The subcellular distribution of invertase was examined after synthesis and secretion by sphaeroplasts had been uncoupled by the addition of 30 microgram mL-1 trypsin. Sphaeroplasts secreted only the high molecular weight invertase during uncoupling by trypsin. The level of low molecular weight, 'small' invertase in the soluble internal pool was found to be elevated by over fivefold, and the membrane-associated pool was found to contain low molecular weight invertase in addition to intermediate molecular weight invertase, after 1.5 h of trypsin treatment. Purified plasma membranes from trypsin-treated sphaeroplasts had no detectable mannan synthetase activity. On the basis of these and previous findings, a working hypothesis wherein invertase is synthesized on the internal surface of the plasma membrane and glycosylated during its transit to the external surface is presented.

UI	MeSH Term	Description	Entries
D008364	Mannosyltransferases	Enzymes that catalyze the transfer of mannose from a nucleoside diphosphate mannose to an acceptor molecule which is frequently another carbohydrate. The group includes EC 2.4.1.32, EC 2.4.1.48, EC 2.4.1.54, and EC 2.4.1.57.	Mannosyltransferase
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D006155	Guanosine Diphosphate Mannose	A nucleoside diphosphate sugar which can be converted to the deoxy sugar GDPfucose, which provides fucose for lipopolysaccharides of bacterial cell walls. Also acts as mannose donor for glycolipid synthesis.	GDP Mannose,Guanosine Diphosphomannose,Guanosine Pyrophosphate Mannose,Diphosphate Mannose, Guanosine,Diphosphomannose, Guanosine,Mannose, GDP,Mannose, Guanosine Diphosphate,Mannose, Guanosine Pyrophosphate,Pyrophosphate Mannose, Guanosine
D012440	Saccharomyces	A genus of ascomycetous fungi of the family Saccharomycetaceae, order SACCHAROMYCETALES.	Saccharomyce
D013104	Spheroplasts	Cells, usually bacteria or yeast, which have partially lost their cell wall, lost their characteristic shape and become round.	Spheroplast
D013393	Sucrase	Digestive enzyme secreted in the INTESTINES. It catalyzes hydrolysis of SUCROSE to FRUCTOSE and GLUCOSE.	Mutansucrase,Sucrose alpha-D-Glucohydrolase,Sucrose alpha D Glucohydrolase,alpha-D-Glucohydrolase, Sucrose
D014357	Trypsin	A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.	Tripcellim,Trypure,beta-Trypsin,beta Trypsin