title: Study of immobilized and extracellular aminopeptidases of watermelon.
abstract: Watermelon cells after permeabilization in Tween 80 were immobilized by glutaraldehyde without any carrier. Cells immobilized by cross-linking demonstrated significantly lower aminopeptidase activities than untreated cells. Pectate and alginate hydrogels were used successfully for immobilization of watermelon cells which retained activities of some aminopeptidases. A simple and rapid procedure for determination of extracellular aminopeptidases was developed using a synthetic substrate. p-Nitroanilides of amino acids were used as substrates for the determination of the extracellular and intracellular enzymatic activities. The culture medium (without cells) was used for the identification and determination of extracellular enzyme activities, whereas intracellular activities were estimated from the cell suspension.
authors.affiliation: Food Research Institute, P.O. Box 25, Priemyselná 4, 824 75 Bratislava 26, Slovakia.
authors.forename: Alfred
authors.initials: A
authors.lastname: Barth
authors.forename: Peter
authors.initials: P
authors.lastname: Siekel
authors.forename: Eva
authors.initials: E
authors.lastname: Sedlárová
authors.forename: Aladár
authors.initials: A
authors.lastname: Valent
authors.forename: Elmíra
authors.initials: E
authors.lastname: Tokhtaeva
mesh_terms: D000464:Alginates / Q000494:pharmacology; D000626:Aminopeptidases / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D000813:Anilides / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D018914:Cells, Immobilized / Q000187:drug effects / Q000201:enzymology; D029773:Citrullus / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D005976:Glutaral / Q000494:pharmacology; D020100:Hydrogels / Q000494:pharmacology; D010368:Pectins / Q000494:pharmacology; D011136:Polysorbates / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000464:Alginates; D000813:Anilides; D020100:Hydrogels; D011136:Polysorbates; D010368:Pectins; D000626:Aminopeptidases; D005976:Glutaral; C003181:polygalacturonic acid