ectoenzyme，lyoenzyme； exoenzyme； extracellular enzyme
Cells within synthesis And the extracellular enzyme 。 It includes enzymes located on the outer surface of cells or in the extracellular space, and also refers to the release of enzymes into culture medium Enzymes. Use this Enzyme catalysis The reaction can avoid destroying the cells. quite a lot Fermentation reaction They are promoted by the action of extracellular enzymes. Such as human and animal Digestive juice Medium and some Bacteria Secretory Hydrolyzed starch 、 Fat and protein Enzymes. This enzyme cytoplasm China and Israel free It can be extracted from cells and purified by the general method of protein fractionation. The extracellular enzyme secretion mechanism can be used Signal peptide hypothesis explain The signal peptide hypothesis holds that the mRNA encoding secreted protein is first synthesized in translation, and the N-terminal is hydrophobic Amino acid residue It is recognized and combined with receptors on the endoplasmic reticulum membrane. Signal peptides reach the lumen of the endoplasmic reticulum through the pores formed by proteins in the membrane, and are randomly hydrolyzed by signal peptidase located on the surface of the lumen. Because of its guidance, new peptides can enter the lumen through the endoplasmic reticulum membrane, and finally be secreted to the outside of the cell. 
