Mutant aminopeptidases of Pisum sativum

Scandalios, John G.; Espiritu, Lucila G.

doi:10.1007/bf00445679

Cited by 28 publications

(2 citation statements)

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“…While naphthylamidase activities in pea have been studied to some extent for genetic control, developmental expression, and biochemical properties (Scandalios & Espiritu, 1969;Scandalios & Campeau, 1972;Elleman, 1974), the maize enzymes have been more extensively investigated with respect to the above parameters. These peptidases appear to have a general metabolic function in cell metabolism and do not have a direct role in the hydrolysis of reserve proteins during germination (Vodkin & Scandalios, 1979).…”

Section: Discussionmentioning

confidence: 99%

Comparative properties of genetically defined peptidases in maize

Vodkin¹,

Scandalios²

1980

Biochemistry

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Four aminopeptidase isozymes (AMP1-AMP4) and an endopeptidase (ENP) from maize have been purified by ammonium sulfate fractionation, DEAE-Sephadex ionexchange chromatography, and Sephadex G-150 gel filtration. Hydroxylapatite chromatography further purified some of the peptidases. Comparisons of molecular weights, substrate specificities, and responses of peptidases to various reagents were made. The aminopeptidases varied in reactivities with the naphthylamide derivatives of amino acids. AMP1 and AMP3 were most active with the arginine and lysine derivatives; AMP2 was most active with the alanine and glycine derivatives and AMP4 was most active with the phenylalanine, tyrosine, leucine, and tryptophan derivatives. Molecular weights as determined by gel filtration on Sephadex G-150 were 92000, 86500, 83000, 61000, and 67600 for AMP1, AMP2, AMP3, AMP4, and ENP1, respectively. AMP2 had a molecular weight of 88000 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. AMP2 hydrolyzed the dipeptide derivatives, glycylglycyl-beta-naphthylamide and glycylphenylalanyl-beta-naphthylamide. Aminopeptidases were strongly inhibited by Zn2+, Cu2+, Hg2+, and p-mercuribenzoate. AMP1, AMP2, and AMP3 were inhibited by 1,10-phenanthroline, whereas AMP4 was not. AMP4 closely resembled aminopeptidases purified from barley grains and pea seeds. ENP was inhibited by p-mercuribenzoate and tosyllysine chloromethyl ketone.

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Section: Discussionmentioning

confidence: 99%

Comparative properties of genetically defined peptidases in maize

Vodkin¹,

Scandalios²

1980

Biochemistry

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“…The supernatant fraction was used to assay for catalase (12), malate synthetase (13), isocitrate lyase (13), aminopeptidase (14), endopeptidase (15), alcohol dehydrogenase (16), malate dehydrogenase (17), glutamic oxalacetic transaminase (18), and superoxide dismutase (19) activity. Protein concentration was determined by the method of Lowry (20).…”

Section: Methodsmentioning

confidence: 99%

Genetic regulation of the catalase developmental program in maize scutellum: Identification of a temporal regulatory gene

Scandalios

Chang

McMillin

et al. 1980

Proc. Natl. Acad. Sci. U.S.A.

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Genetic and biochemical analyses suggest that the developmental program of catalase (H 2 O 2 :H 2 O 2 oxidoreductase, EC 1.11.1.6) activity in maize scutella is controlled by a temporal regulatory gene ( Car1 ) that is distinct from the structural genes thus far identified. Recombination data show that Car1 is located about 37 map units from the Cat2 structural gene on the chromosome 1S. Turnover studies indicate that Car1 may act by regulating the rate of catalase synthesis.

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Electrophoretic Evidence for Genetic Diploidy in Psilotum Nudum

Soltis

1988

American J of Botany

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Psilotum nudum (2n = 104) has been considered an ancient polyploid, having resulted from repeated cycles of hybridization and allopolyploidy. However, electrophoretic analysis indicates that this species is genetically diploid despite its high chromosome number. Sixteen enzymes, encoded by 28 loci, revealed in P. nudum the number of isozymes typical of diploid seed plants. There is, therefore, no evidence of polyploid gene expression for the enzymes analyzed. These results for Psilotophyta are similar to those obtained for other lineages of homosporous pteridophytes, i.e., Arthrophyta and homosporous Microphyllophyta and Pteridophyta, all of which should be considered genetically diploid. Several hypotheses have been proposed to explain these results, most notably 1) cycles of allopolyploidy followed by massive gene silencing, and 2) initiation of these lineages with high chromosome numbers, possibly via chromosomal fission. Discrimination between these hypotheses awaits testing with molecular genetic techniques.

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Mutant aminopeptidases of Pisum sativum

Cited by 28 publications

References 12 publications

Comparative properties of genetically defined peptidases in maize

Comparative properties of genetically defined peptidases in maize

Genetic regulation of the catalase developmental program in maize scutellum: Identification of a temporal regulatory gene

Electrophoretic Evidence for Genetic Diploidy in Psilotum Nudum

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