John Scandalios - Academia.edu (original) (raw)

Papers by John Scandalios

Research paper thumbnail of Molecular genetics of development

Molecular genetics of development

Academic Press eBooks, 1987

Research paper thumbnail of Gene expression and development : the 3rd of five volumes constituting the proceedings of the 4th International Congress on Isozymes, Austin, Texas, Jun 14-19, 1982

Gene expression and development : the 3rd of five volumes constituting the proceedings of the 4th International Congress on Isozymes, Austin, Texas, Jun 14-19, 1982

Research paper thumbnail of Molecular and cellular biology : the first of three volumes constituting the proceedings of the 5th International Congress on Isozymes held in Kos, Greece, May 26-29, 1986

Molecular and cellular biology : the first of three volumes constituting the proceedings of the 5th International Congress on Isozymes held in Kos, Greece, May 26-29, 1986

Liss eBooks, 1987

Research paper thumbnail of Molecular structure and regulation : the first of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Molecular structure and regulation : the first of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Liss eBooks, 1983

Research paper thumbnail of Developmental Analysis of Steady-State Levels of Cu/Zn and Mn Superoxide Dismutase mRNAs in Maize Tissues

Developmental Analysis of Steady-State Levels of Cu/Zn and Mn Superoxide Dismutase mRNAs in Maize Tissues

Plant and Cell Physiology, 1990

En etudiant les differences de quantites en RNAm de la superoxide dismutase (Sod) du cytosol (Cu/... more En etudiant les differences de quantites en RNAm de la superoxide dismutase (Sod) du cytosol (Cu/Zn) ou mitochondriale (Mn), on essaie de determiner l'expression relative des genes de la Sod durant le developpement de certains tissus chez le mais afin de savoir si les proteines mitochondriales codees par des genes nucleaires sont independamment regules ou egalement regules

Research paper thumbnail of Effects of Cycloheximide and Chloramphenicol on the Synthesis of Polypeptides Found in Three Subcellular Fractions of Maize Scutellum

Plant Physiology, Jun 1, 1977

The effects of two protein synthesis hinbitors, cydoheximide and chloramphenicol, on the synthesi... more The effects of two protein synthesis hinbitors, cydoheximide and chloramphenicol, on the synthesis of nitochondrial proteins in maize (Zea mays) have been studied. The results of these investigations suggest that while most of the mitochondrial proteins are synthesized in the cytoplasm and are subsequently asociated wth the nitochondrion, several proteins of the mitochondrial inner membrane are synthesized within the mitochondrion. These resut are consistent with those observed in several other systems, but not previously reported for higher p-ts. of CH or CAP. The sets were then mixed and homogenized. The 3H incorporation thus served as an internal standard, and the 3H/ 14C ratio served as an indicator of the influence of the protein synthesis inhibitors. SUBCELLULAR FRACTIONS Various subcellular fractions were obtained as described by Longo and Longo (10). Three fractions were studied, namely the soluble fraction (25,000g supernatant), the mitochondrial fraction (which banded at an isopycnic density of 1.22 g/cm3 in a 35-65% sucrose gradient), and the dense particulate fraction which passed through the 65% sucrose in the gradients. This fraction contained mitochondrial inner membranes and glyoxysomes. In higher organisms, protein synthesis occurs on both 80S (cytoplasmic) and 70S (mitochondrial) ribosomes. In yeast, Neurospora, and mammals (2, 13, 14, 16), less than 10% of the

Research paper thumbnail of Purification and Partial Characterization of a Genetically-Defined Superoxide Dismutase (SOD-1) Associated with Maize Chloroplasts

Plant Physiology, Sep 1, 1983

The chloroplast-associated form of superoxide dismuase from maize (Zea mays L.) (SOD-i) has been ... more The chloroplast-associated form of superoxide dismuase from maize (Zea mays L.) (SOD-i) has been purified by a stepwise procedure consisting of (NH4)2SO4 fractionation, G-100 Sephadex gel filtration, DEAE-Sephacel chromatography, and hydroxylapatite chromatography. This procedure resulted in a single band on sodium dodecyl sulfatepolyacrylamide gels indicating that the preparation is homogeneous. The holoenzyme molecular weight was estimated at 31,000 to 33,000 by gel filtration. The subunit molecular weight of this dimeric protein was estimated at 14,500 on sodium dodecyl sulfate-polyacrylamide gels. Studies involving amino acid composition analysis, immunological crossreactivity, in vitro subunit hybridizations, and H202 sensitivity indicate that SOD-i differs significantly from SOD-2 and SOD4, the other cupro-zinc forms of SOD from maize. The possible physiological role of SOD-i within the chloroplast is discussed.

Research paper thumbnail of Genetics of Leucine Aminopeptidase Isozymes in Maize

Genetics, Nov 2, 1964

a combination of starch gel electrophoresis and various enzyme staining BLhniques multiple molecu... more a combination of starch gel electrophoresis and various enzyme staining BLhniques multiple molecular forms of enzymes have been demonstrated in a large variety of organisms. MARKERT and MBLLER (1959) introduced the concept of an isozyme, defined as one of the molecular forms of an enzyme. In maize some highly interesting results have been found concerning esterase (SCHWARTZ 1960a, 1962~1, b, 1964) and alkaline phosphatase (SCHWARTZ 1960b). This report deals with the genetic control of leucine aminopeptidase (LAP) isozymes in maize. The genetics of this enzyme system has not been studied very extensively and to our knowledge there have been no previous studies of LAP in plants. The only organism in which genetic variations in this enzyme have been demonstrated is Drosophila melanogaster (BECKMAN and JOHNSON 1964). MATERIALS A N D METHODS Maize ears were harvested on the 16th day after pollination. The fresh liquid endosperm from individual kernels was squeezed onto a piece of filter paper (5x5 mm) to be inserted into a starch gel. Kernels stored up to one month under refrigeration provided usable samples. Homogenates were also prepared from leaf, husk, pollen and young seedlings. Starch gel electrophoresis was carried out in a discontinuous buffer system, p H 8.6, (ASHTON and BRADEN 1961)

Research paper thumbnail of Gene expression during early kernel development of Zea mays

Gene expression during early kernel development of Zea mays

Genetics, 1980

Research paper thumbnail of The antioxidant enzyme genes Cat and Sod of maize: regulation, functional significance, and molecular biology

The antioxidant enzyme genes Cat and Sod of maize: regulation, functional significance, and molecular biology

PubMed, 1987

Research paper thumbnail of Genetic Control of Multiple Molecular Forms of Catalase in Maize

Annals of the New York Academy of Sciences, Jun 1, 1968

Research paper thumbnail of Medical and other applications : the fifth of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Medical and other applications : the fifth of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Liss eBooks, 1983

Research paper thumbnail of Cellular localization, metabolism, and physiology : the second of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Cellular localization, metabolism, and physiology : the second of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Liss eBooks, 1983

Research paper thumbnail of Isozymes: Organization and Roles in Evolution, Genetics and Physiology

Isozymes: Organization and Roles in Evolution, Genetics and Physiology

Research paper thumbnail of Further biochemical and genetic characterizations of superoxide dismutase from maize

Further biochemical and genetic characterizations of superoxide dismutase from maize

Genetics, 1980

Research paper thumbnail of Human Serum Leucine Aminopeptidase

Human Serum Leucine Aminopeptidase

Journal of Heredity, May 1, 1967

Research paper thumbnail of Isolation, characterization and expression of the maize Cat2 catalase gene

Plant Molecular Biology, Mar 1, 1996

The maize Cat2 gene was isolated by direct cloning and PCR. The clones were mapped and sequenced.... more The maize Cat2 gene was isolated by direct cloning and PCR. The clones were mapped and sequenced. The start site of transcription was determined by primer extension. Computer analysis of the 1.6 kb Cat2 promoter sequence has revealed an obvious TATA box, two GC boxes, a putative GA response element, and several ACGT core sequences known to have diverse regulatory functions in plants. Several other protein binding motifs were also identified within 800 bp upstream from the transcriptional start site. Five introns were identified in the Cat2 coding region. All five Cat2 introns are located in exactly the same position as five of the six introns in Catl, Two of the Cat2 introns are located in the same position as the two Cat3 introns. The identical positioning of these introns suggests an evolutionary link between all three maize cat&se genes. The response of the Cat2 gene to plant growth regulators was examined. Results clearly showed that the response of Cat2 to several environmental factors are developmental stage-dependent. Thus. complex regulatory mechanisms appear to be involved in the regulation of Cat2 expression in maize.

Research paper thumbnail of Purification and partial characterization of two genetically defined alcohol dehydrogenase isozymes in maize

Purification and partial characterization of two genetically defined alcohol dehydrogenase isozymes in maize

Biochimica Et Biophysica Acta - Proteins And Proteomics, Jul 1, 1973

Abstract Two of the isozymes of maize alcohol dehydrogenase (2F and 2S) specified by alleles at t... more Abstract Two of the isozymes of maize alcohol dehydrogenase (2F and 2S) specified by alleles at the Adh 2 gene locus have been purified and studied. Isozyme 2S has a lower specific activity and is more heat labile than isozyme 2F, but the two forms have similar K m values, pH optima and molecular weight. Amino acid analysis of the acid hydrolysates of isozymes 2F and 2S show striking similarities in the amino acid composition even though 2S is not purified to homogeneity. This suggests that these molecules differ by only one or a few amino acids.

Research paper thumbnail of Isolation and characterization of the cytosolic and mitochondrial superoxide dismutases of maize

Isolation and characterization of the cytosolic and mitochondrial superoxide dismutases of maize

Archives of Biochemistry and Biophysics, Feb 1, 1981

ABSTRACT The cytosolic and mitochondrial forms of Superoxide dismutase have been purified to homo... more ABSTRACT The cytosolic and mitochondrial forms of Superoxide dismutase have been purified to homogeneity from an inbred line of maize. The cytosolic isozymes SOD-2 and SOD-4 are dimers with a molecular weight of 31,000–33,000, composed of apparently equal subunits, and are remarkably similar with respect to their ultraviolet absorption spectra, antigenic specificity, and sensitivity to cyanide, azide, hydrogen peroxide, and diethyldithiocarbamate. These and other data suggest that both isozymes belong to the family of copper and zinc-containing Superoxide dismutases. The mitochondrial isozyme, SOD-3, is unlike the cytosolic isozymes in every parameter studied and appears to be similar to the mitochondrial manganese-containing Superoxide dismutases purified from other eukaryotic organisms. It is a tetramer with a molecular weight of approximately 90,000, composed of apparently equal subunits, and is insensitive to both 1 mm cyanide and hydrogen peroxide.

Research paper thumbnail of Genetic control of multiple molecular forms of enzymes in plants: A review

Biochemical Genetics, Feb 1, 1969

Research paper thumbnail of Molecular genetics of development

Molecular genetics of development

Academic Press eBooks, 1987

Research paper thumbnail of Gene expression and development : the 3rd of five volumes constituting the proceedings of the 4th International Congress on Isozymes, Austin, Texas, Jun 14-19, 1982

Gene expression and development : the 3rd of five volumes constituting the proceedings of the 4th International Congress on Isozymes, Austin, Texas, Jun 14-19, 1982

Research paper thumbnail of Molecular and cellular biology : the first of three volumes constituting the proceedings of the 5th International Congress on Isozymes held in Kos, Greece, May 26-29, 1986

Molecular and cellular biology : the first of three volumes constituting the proceedings of the 5th International Congress on Isozymes held in Kos, Greece, May 26-29, 1986

Liss eBooks, 1987

Research paper thumbnail of Molecular structure and regulation : the first of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Molecular structure and regulation : the first of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Liss eBooks, 1983

Research paper thumbnail of Developmental Analysis of Steady-State Levels of Cu/Zn and Mn Superoxide Dismutase mRNAs in Maize Tissues

Developmental Analysis of Steady-State Levels of Cu/Zn and Mn Superoxide Dismutase mRNAs in Maize Tissues

Plant and Cell Physiology, 1990

En etudiant les differences de quantites en RNAm de la superoxide dismutase (Sod) du cytosol (Cu/... more En etudiant les differences de quantites en RNAm de la superoxide dismutase (Sod) du cytosol (Cu/Zn) ou mitochondriale (Mn), on essaie de determiner l'expression relative des genes de la Sod durant le developpement de certains tissus chez le mais afin de savoir si les proteines mitochondriales codees par des genes nucleaires sont independamment regules ou egalement regules

Research paper thumbnail of Effects of Cycloheximide and Chloramphenicol on the Synthesis of Polypeptides Found in Three Subcellular Fractions of Maize Scutellum

Plant Physiology, Jun 1, 1977

The effects of two protein synthesis hinbitors, cydoheximide and chloramphenicol, on the synthesi... more The effects of two protein synthesis hinbitors, cydoheximide and chloramphenicol, on the synthesis of nitochondrial proteins in maize (Zea mays) have been studied. The results of these investigations suggest that while most of the mitochondrial proteins are synthesized in the cytoplasm and are subsequently asociated wth the nitochondrion, several proteins of the mitochondrial inner membrane are synthesized within the mitochondrion. These resut are consistent with those observed in several other systems, but not previously reported for higher p-ts. of CH or CAP. The sets were then mixed and homogenized. The 3H incorporation thus served as an internal standard, and the 3H/ 14C ratio served as an indicator of the influence of the protein synthesis inhibitors. SUBCELLULAR FRACTIONS Various subcellular fractions were obtained as described by Longo and Longo (10). Three fractions were studied, namely the soluble fraction (25,000g supernatant), the mitochondrial fraction (which banded at an isopycnic density of 1.22 g/cm3 in a 35-65% sucrose gradient), and the dense particulate fraction which passed through the 65% sucrose in the gradients. This fraction contained mitochondrial inner membranes and glyoxysomes. In higher organisms, protein synthesis occurs on both 80S (cytoplasmic) and 70S (mitochondrial) ribosomes. In yeast, Neurospora, and mammals (2, 13, 14, 16), less than 10% of the

Research paper thumbnail of Purification and Partial Characterization of a Genetically-Defined Superoxide Dismutase (SOD-1) Associated with Maize Chloroplasts

Plant Physiology, Sep 1, 1983

The chloroplast-associated form of superoxide dismuase from maize (Zea mays L.) (SOD-i) has been ... more The chloroplast-associated form of superoxide dismuase from maize (Zea mays L.) (SOD-i) has been purified by a stepwise procedure consisting of (NH4)2SO4 fractionation, G-100 Sephadex gel filtration, DEAE-Sephacel chromatography, and hydroxylapatite chromatography. This procedure resulted in a single band on sodium dodecyl sulfatepolyacrylamide gels indicating that the preparation is homogeneous. The holoenzyme molecular weight was estimated at 31,000 to 33,000 by gel filtration. The subunit molecular weight of this dimeric protein was estimated at 14,500 on sodium dodecyl sulfate-polyacrylamide gels. Studies involving amino acid composition analysis, immunological crossreactivity, in vitro subunit hybridizations, and H202 sensitivity indicate that SOD-i differs significantly from SOD-2 and SOD4, the other cupro-zinc forms of SOD from maize. The possible physiological role of SOD-i within the chloroplast is discussed.

Research paper thumbnail of Genetics of Leucine Aminopeptidase Isozymes in Maize

Genetics, Nov 2, 1964

a combination of starch gel electrophoresis and various enzyme staining BLhniques multiple molecu... more a combination of starch gel electrophoresis and various enzyme staining BLhniques multiple molecular forms of enzymes have been demonstrated in a large variety of organisms. MARKERT and MBLLER (1959) introduced the concept of an isozyme, defined as one of the molecular forms of an enzyme. In maize some highly interesting results have been found concerning esterase (SCHWARTZ 1960a, 1962~1, b, 1964) and alkaline phosphatase (SCHWARTZ 1960b). This report deals with the genetic control of leucine aminopeptidase (LAP) isozymes in maize. The genetics of this enzyme system has not been studied very extensively and to our knowledge there have been no previous studies of LAP in plants. The only organism in which genetic variations in this enzyme have been demonstrated is Drosophila melanogaster (BECKMAN and JOHNSON 1964). MATERIALS A N D METHODS Maize ears were harvested on the 16th day after pollination. The fresh liquid endosperm from individual kernels was squeezed onto a piece of filter paper (5x5 mm) to be inserted into a starch gel. Kernels stored up to one month under refrigeration provided usable samples. Homogenates were also prepared from leaf, husk, pollen and young seedlings. Starch gel electrophoresis was carried out in a discontinuous buffer system, p H 8.6, (ASHTON and BRADEN 1961)

Research paper thumbnail of Gene expression during early kernel development of Zea mays

Gene expression during early kernel development of Zea mays

Genetics, 1980

Research paper thumbnail of The antioxidant enzyme genes Cat and Sod of maize: regulation, functional significance, and molecular biology

The antioxidant enzyme genes Cat and Sod of maize: regulation, functional significance, and molecular biology

PubMed, 1987

Research paper thumbnail of Genetic Control of Multiple Molecular Forms of Catalase in Maize

Annals of the New York Academy of Sciences, Jun 1, 1968

Research paper thumbnail of Medical and other applications : the fifth of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Medical and other applications : the fifth of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Liss eBooks, 1983

Research paper thumbnail of Cellular localization, metabolism, and physiology : the second of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Cellular localization, metabolism, and physiology : the second of five volumes constituting the proceedings of the 4th International Congress on Isozymes held in Austin, Texas, June 14-19, 1982

Liss eBooks, 1983

Research paper thumbnail of Isozymes: Organization and Roles in Evolution, Genetics and Physiology

Isozymes: Organization and Roles in Evolution, Genetics and Physiology

Research paper thumbnail of Further biochemical and genetic characterizations of superoxide dismutase from maize

Further biochemical and genetic characterizations of superoxide dismutase from maize

Genetics, 1980

Research paper thumbnail of Human Serum Leucine Aminopeptidase

Human Serum Leucine Aminopeptidase

Journal of Heredity, May 1, 1967

Research paper thumbnail of Isolation, characterization and expression of the maize Cat2 catalase gene

Plant Molecular Biology, Mar 1, 1996

The maize Cat2 gene was isolated by direct cloning and PCR. The clones were mapped and sequenced.... more The maize Cat2 gene was isolated by direct cloning and PCR. The clones were mapped and sequenced. The start site of transcription was determined by primer extension. Computer analysis of the 1.6 kb Cat2 promoter sequence has revealed an obvious TATA box, two GC boxes, a putative GA response element, and several ACGT core sequences known to have diverse regulatory functions in plants. Several other protein binding motifs were also identified within 800 bp upstream from the transcriptional start site. Five introns were identified in the Cat2 coding region. All five Cat2 introns are located in exactly the same position as five of the six introns in Catl, Two of the Cat2 introns are located in the same position as the two Cat3 introns. The identical positioning of these introns suggests an evolutionary link between all three maize cat&se genes. The response of the Cat2 gene to plant growth regulators was examined. Results clearly showed that the response of Cat2 to several environmental factors are developmental stage-dependent. Thus. complex regulatory mechanisms appear to be involved in the regulation of Cat2 expression in maize.

Research paper thumbnail of Purification and partial characterization of two genetically defined alcohol dehydrogenase isozymes in maize

Purification and partial characterization of two genetically defined alcohol dehydrogenase isozymes in maize

Biochimica Et Biophysica Acta - Proteins And Proteomics, Jul 1, 1973

Abstract Two of the isozymes of maize alcohol dehydrogenase (2F and 2S) specified by alleles at t... more Abstract Two of the isozymes of maize alcohol dehydrogenase (2F and 2S) specified by alleles at the Adh 2 gene locus have been purified and studied. Isozyme 2S has a lower specific activity and is more heat labile than isozyme 2F, but the two forms have similar K m values, pH optima and molecular weight. Amino acid analysis of the acid hydrolysates of isozymes 2F and 2S show striking similarities in the amino acid composition even though 2S is not purified to homogeneity. This suggests that these molecules differ by only one or a few amino acids.

Research paper thumbnail of Isolation and characterization of the cytosolic and mitochondrial superoxide dismutases of maize

Isolation and characterization of the cytosolic and mitochondrial superoxide dismutases of maize

Archives of Biochemistry and Biophysics, Feb 1, 1981

ABSTRACT The cytosolic and mitochondrial forms of Superoxide dismutase have been purified to homo... more ABSTRACT The cytosolic and mitochondrial forms of Superoxide dismutase have been purified to homogeneity from an inbred line of maize. The cytosolic isozymes SOD-2 and SOD-4 are dimers with a molecular weight of 31,000–33,000, composed of apparently equal subunits, and are remarkably similar with respect to their ultraviolet absorption spectra, antigenic specificity, and sensitivity to cyanide, azide, hydrogen peroxide, and diethyldithiocarbamate. These and other data suggest that both isozymes belong to the family of copper and zinc-containing Superoxide dismutases. The mitochondrial isozyme, SOD-3, is unlike the cytosolic isozymes in every parameter studied and appears to be similar to the mitochondrial manganese-containing Superoxide dismutases purified from other eukaryotic organisms. It is a tetramer with a molecular weight of approximately 90,000, composed of apparently equal subunits, and is insensitive to both 1 mm cyanide and hydrogen peroxide.

Research paper thumbnail of Genetic control of multiple molecular forms of enzymes in plants: A review

Biochemical Genetics, Feb 1, 1969