Biomaterial Database

Purification and properties of a 4-methylene-L-glutamine amidohydrolase from peanut leaves. 1983

G K Powell, and E E Dekker

A 4-methylene-L-glutamine amidohydrolase has been partially purified from leaf extracts of 2-week germinated peanuts (Arachis hypogaea). Purification steps include DEAE-Sephacel and gel filtration chromatography as well as chromatofocusing; amidohydrolase purified 300- to 400-fold is obtained. The enzyme has an approximate molecular weight of 45,000 as determined by gel filtration chromatography and polyacrylamide gel electrophoresis, a broad activity optimum between pH 8.0 and 9.0, and is highly specific toward 4-methylene-L-glutamine. Of a number of amides tested as substrate, only L-glutamine serves 20% as effectively as the methylene-substituted analog. Multiple bands of activity, seen when enzyme samples are electrophoresed on polyacrylamide gels, are not completely resolved but appear to be very similar in molecular weight, pK values, and subcellular localization. Activity is not affected either by added thiols, metal ions, sulfhydryl-reacting reagents, or metal-ion chelators; it is inhibited by borate ions but stimulated by sodium dodecyl sulfate. This amidohydrolase activity is absent in imbibed seeds, but on germination increases rapidly in the cotyledons and leaves for 3 weeks followed by a gradual decline as the plant matures. Activity is almost completely (95%) localized in the leaves and cotyledons. Differential centrifugation studies indicate that the enzyme is found solely in the soluble fraction of peanut leaves.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010367	Arachis	A plant genus of the family FABACEAE that includes peanuts.	Arachis hypogaea,Peanuts,Peanut
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D002412	Cations	Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.	Cation
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D000581	Amidohydrolases	Any member of the class of enzymes that catalyze the cleavage of amide bonds and result in the addition of water to the resulting molecules.	Amidases,Amidohydrolase
D000838	Anions	Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.	Anion
D013347	Subcellular Fractions	Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)	Fraction, Subcellular,Fractions, Subcellular,Subcellular Fraction
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities
D063245	Plant Development	Processes orchestrated or driven by a plethora of genes, plant hormones, and inherent biological timing mechanisms facilitated by secondary molecules, which result in the systematic transformation of plants and plant parts, from one stage of maturity to another.	Plant Morphogenesis,Development, Plant,Developments, Plant,Morphogeneses, Plant,Morphogenesis, Plant,Plant Developments,Plant Morphogeneses