Wlasciwosci enzymu wyklucia zarodkow ryb glabielowatych [Coregonidae]

• Autorzy: Luberdo-Bienkowska Z
• Języki publikacji: PL

Abstrakty

PL

W pracy określono właściwości enzymu, który trawi osłonę jajową podczas procesu wykluwania się zarodków ryb głąbielowatych (Coregonidae). Enzym wyklucia (chorionaza) głąbielowatych jest białkiem o budowie monomerycznej, wykazującym właściwości antygenowe. Masa cząsteczkowa enzymu określona w SDS-PAGE wynosi ok. 12 kDa. Badania składu i wpływu jonów oraz inhibitorów na aktywność enzymu pozwalają zakwalifikować go do metaloproteinaz zawierających Zn2+ w centrum aktywnym. Enzym wyklucia ryb głąbielowatych wykazuje maksymalną aktywność proteolityczną w temp. 25°C i pH 8.4-9.2. Badaną chorionazę charakteryzuje niewielka aktywność katalitycz­na już w temp. 2°C. Enzym jest termolabilny. Produkty wolnorodnikowego utleniania lipidów wpływają toksycznie na jego aktywność. Metodą fluoroscencyjną przy użyciu syntetycznych peptydów znakowanych kumaryną wykryto, że enzym wyklucia zarodków ryb głąbielowatych wykazuje wysoką specyficzność wobec wiązań peptydowych utworzonych przez reszty leucyny i waliny, a także tyrozyny. Produktami enzymatycznego trawienia wewnętrznej warstwy chorionu są głównie rozpuszczalne białka i niewielkie ilości wolnych aminokwasów. Enzym nie wykazuje aktywności esterazowej i amidazowej. Jest gatunkowo niespecyficzny wobec chorionów ryb głąbielowatych i łososiowatych (Salmonidae). Przy użyciu skaningowego mikroskopu elektronowego wykazano morfologiczne zmiany ultrastruktury osłony jajowej podczas procesu jej trawienia przez enzym wyklucia. Stwierdzono, że chorionaza głąbielowatych i analogiczne enzymy zarodków ryb należących do rodziny łososiowatych, żyjących w wodach Polski i Norwegii, wykazują zbliżone właściwości biochemiczne.

EN

The study has determined the properties of the hatching enzyme which digests the egg envelope during coregonid (Coregonidae) embryo hatching. The hatching enzyme (chorionase) of coregonid fishes is a monomeric protein showing antigenic properties. Molecular weight of the enzyme determined in SDS-PAGE amounts to about 12 kDa. Studies on the composition and the effect of ions and inhibitors upon activity of the enzyme have revealed that the enzyme may be classified as a metalloproteinase containing Zn2+ in the active centre. Hatching enzyme of the coregonids shows maximal proteolytic activity in 25°C and pH 8.4-9.2. The chorionase is characterized by low catalytic activity already in 2°C. The enzyme is thermolabile. Products of free radical lipid oxidation have a toxic effect on its activity. The fluorescence method using synthetic peptides labelled with coumarin has revealed that the hatching enzyme of coregonid embryos shows high specificity towards peptide bonds formed by leucine and valine and also tyrosine residues. Soluble proteins and some free amino acids are the major products of enzymatic digestion of the inner layer of chorion. The enzyme does not show esterase and amidase activity. It is not species-specific as regards chorions of coregonids and salmonids (Salmonidae). Scanning microscopy has been used to demonstrate morphologic changes in the ultrastructure of egg envelope in course of its digestion by the hatching enzyme. It has been found that chorionase of coregonids and analogous enzymes of the embryos of salmonid fishes inhabiting Polish and Norwegian waters are charactrized by similar biochemi­cal properties.

Słowa kluczowe

PL

biochemia zwierzat; ryby; Coregonidae; glabielowate; zarodki; enzymy; enzym wyklucia; wlasciwosci biochemiczne; oslona jajowa

EN

animal biochemistry; fish; Coregonidae; embryo; enzyme; hatching enzyme; biochemical property; egg envelope

• Wydawca: -
• Czasopismo: Acta Academiae Agriculturae ac Technicae Olstenensis. Zootechnica
• Rocznik: 1995
• Tom: 42,Suppl.A
• Opis fizyczny: s.44,rys.,fot.,tab.,bibliogr.

Twórcy

autor

Luberdo-Bienkowska Z

• Akademia Rolniczo-Techniczna, Olsztyn

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