Search results for "Sephadex"
showing 6 items of 26 documents
Localization and Activity of a Carboxypeptidase in Germinating Seeds of Scots Pine, Pinus sylvestris
1976
Extracts prepared from the endosperm of germinating seeds of Scots pine, Pinus sylvestris L., hydrolysed two typical carboxypeptidase substrates, Z-Phe-Ala and Z-Phe-Phe, with pH optima at 4.2 and 5.0. The activities were completely destroyed by diisopropylfluorophosphate. Identical heat inactivation curves and elution patterns in gel chromatography on Sephadex G-200 suggest that the two activities are due to a single enzyme. In resting seeds very low carboxypeptidase activity was present in both the endosperm and the embryo. During germination on agar gel at 20°C in the dark the activities, expressed as enzyme units per seed, increased in the seedling and particularly in the endosperm up t…
Preparation of extracts from mature spruce needles for enzymatic analyses
1987
It was possible to extract simultaneously several active enzymes involved in the carbohydrate or the amino acid metabolism from spruce needles [Picea abies (L.) Karst.] when a) a 100 mM Na-Pi buffer of pH 7.5 containing 5% PVPP and 0.5% Triton X-100 was used and when b) the resulting crude extracts were freed from lowmolecular-weight compounds by gel-chromatography using the separation medium Fractogel TSK HW-40. Besides Triton X-100, Triton X-305, Myrij-52 and Brij-35 were tested, but 0.5% Triton X-100 brought about the most active enzyme extracts. In crude extracts prepared from spruce needles during the early summer a high increase in absorbance at 334 nm was observed when the co-substra…
Gelchromatographie. 1. Mitt. Trennung von oligomeren
1966
Vernetzte Polymere werden hergestellt und ihre Eignung zur gelchromatographischen Trennung von Gemischen von Oligomeren gepruft; im einzelnen wurden untersucht: mit Isocyanaten modifiziertes Sephadex; Polymethyl-und Polybutylmethacrylat, vernetzt mit Glykoldimethacrylat bzw. mit Polyathylenoxid-dimethacrylat; Polyvinylacetat, vernetzt mit n-Butandioldivinylather; Polystrol, vernetzt mit Divinylbenzol; ferner Silicagel. Der Einflus der Molekulgestalt auf das Elutionsvolumen wurde gepruft. Die Elutionsvolumina von p-Oligophenylenen, die eine stabchenformige Molekulgestalt besitzen, sind groser als die von Oligourethanen gleichen Molekulargewichts; o- und m-gewinkelte Oligophenylene zeigen geg…
Effect of cadmium pre-exposure in cadmium accumulation by brine shrimp Artemia: Involvement of low-molecular-weight cadmium-binding ligands
1993
Abstract Cadmium is a ubiquitous non-essential element that possesses high toxicity and is easily accumulated from the environment by aquatic organisms. It is known that pre-exposure to cadmium increases the resistance of animals to a subsequent exposure. In this work, we report studies of the effect of pre-exposure to cadmium on the accumulation of this metal from seawater by brine shrimp Artemia, as well as the involvement of low-molecular-weight cadmium-binding ligands in this process. During the pre-exposure experiments, animals were kept in seawater containing 20 mg/litre Cd for 24 h and then transferred to clean seawater for 48 h. Afterwards, pre-exposed and control animals were expos…
Anti-phospholipase A2 and anti-inflammatory activity of Santolina chamaecyparissus
2000
The activity of the Santolina chamaecyparissus methanol extract was tested against the phospholipase A2 (PLA2)-induced mouse paw edema and in vitro inhibition of PLA2 activity. After fractionation, only the dichloromethane extract was active against the PLA2 in vitro test. In addition, it reduced the edema induced by arachidonic acid, and by 12-O-tetradecanoylphorbol-13-acetate in a multidose test. After chromatography on silicagel and gel filtration on Sephadex, and using an in vitro anti-PLA2 assay-guided process, we have isolated and identified from the dichloromethane extract the flavone nepetin and four sesquiterpenes.
Purification and partial characterization of aminopeptidase from barley (Hordeum vulgare L.) seeds.
2013
Aminopeptidases (EC 3.4.11) are proteolytic enzymes, which hydrolyze one amino acid from N-terminus of peptidic substrates. Inhibitors of plant aminopeptidases can find an application in agriculture as herbicides. Isolation and partial characterization of aminopeptidase from barley (Hordeum vulgare L.) seeds has been described. The enzyme was purified to molecular homogeneity using a six-step purification procedure (precipitation with (NH4)2SO4, followed by chromatography on Sephadex G-25, DEAE-Sepharose, Sephacryl HR 300, Macro-Prep Q and Phenyl-Sepharose HP columns). The enzyme was purified 365-fold with recovery above 18%. The molecular weight of the purified enzyme was determined by SDS…