Purification and properties of the apple fruit ethylene-forming enzyme

Pirrung, Michael C.; Kaiser, Lynn M.; Chen, Jrlung

doi:10.1021/bi00080a015

Cited by 49 publications

(31 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In these experiments, the antibodies raised against TRACO2 identified an ACC oxidase protein of 36.4 kD, which is within the size range (35-41 kD) reported for ACC oxidase proteins from other plant species (Dong et al, 1992;Dupille et al, 1993;Pirrung et al, 1993;Rombaldi et al, 1994), and the relative accumulation of the protein determined by western blotting matched the measurable ACO activity in vitro. The TRACO1 antibody recognized a protein of approximately 205 kD that was expressed predominantly in the apex.…”

Section: Discussionsupporting

confidence: 82%

“…ACC oxidase has now been purified to homogeneity and characterized from apple fruits (Dong et al, 1992; Dupille et al, 1993;Pirrung et al, 1993) and partially purified and characterized from a range of tissues, including apple (FernandezMaculet and Yang, 1992;Kuai and Dilley, 1992), avocado (McGarvey and Christoffersen, 1992), pear (Vioque and Castellano, 1994), and citrus (Dupille and Zacarias, 1996).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Expression of 1-Aminocyclopropane-1-Carboxylate Oxidase during Leaf Ontogeny in White Clover1

et al. 1999

View full text Add to dashboard Cite

We examined the expression of three distinct 1-aminocyclopropane-1-carboxylic acid oxidase genes during leaf ontogeny in white clover (Trifolium repens). Significant production of ethylene occurs at the apex, in newly initiated leaves, and in senescent leaf tissue. We used a combination of reverse transcriptase-polymerase chain reaction and 3-rapid amplification of cDNA ends to identify three distinct DNA sequences designated TRACO1, TRACO2, and TRACO3, each with homology to 1-aminocyclopropane-1-carboxylic acid oxidase. Southern analysis confirmed that these sequences represent three distinct genes. Northern analysis revealed that TRACO1 is expressed specifically in the apex and TRACO2 is expressed in the apex and in developing and mature green leaves, with maximum expression in developing leaf tissue. The third gene, TRACO3, is expressed in senescent leaf tissue. Antibodies were raised to each gene product expressed in Escherichia coli, and western analysis showed that the TRACO1 antibody recognizes a protein of approximately 205 kD (as determined by gradient sodium dodecyl sulfate-polyacylamide gel electrophoresis) that is expressed preferentially in apical tissue. The TRACO2 antibody recognizes a protein of approximately 36.4 kD (as determined by gradient sodium dodecyl sulfate-polyacylamide gel electrophoresis) that is expressed in the apex and in developing and mature green leaves, with maximum expression in mature green tissue. No protein recognition by the TRACO3 antibody could be detected in senescent tissue or at any other stage of leaf development.The plant hormone ethylene is an important regulator of several physiological processes in higher plants (Abeles et al., 1992) and also functions as a mediator of responses to external stimuli, such as wounding, flooding, and pathogen invasion (Kende, 1993). The biosynthetic pathway of the hormone in higher plants has now been characterized (Adams and Yang, 1979) and two committed enzymes in the pathway, ACC synthase (EC 4.4.1.14) and ACC oxidase (EC 1.4.3), have been identified (Yang and Hoffman, 1984;Kende, 1993).ACC synthase is recognized as the rate-determining step in the ethylene-biosynthesis pathway, and many inducers are proposed to act by stimulation of this enzyme (Yang and Hoffman, 1984;Theologis, 1992;Kende, 1993). The enzyme is known to be coded for by a multigene family in several plant species, with many of these genes cloned from a wide variety of tissues and in response to a variety of stimuli (Fluhr and Mattoo, 1996).In contrast, the ability of most plant tissues to convert ACC to ethylene was interpreted originally as evidence that the regulation of ACC oxidase is not a major control point of ethylene biosynthesis (Yang and Hoffman, 1984). More recently, two significant advances have provided the foundation for more detailed biochemical analysis of the enzyme. The first was the expression of a cDNA, designated pTOM13, coding for the putative ethylene-forming enzyme (Hamilton et al., 1990) in yeast (Hamilton et al., 1991), and another hi...

show abstract

Section: Discussionsupporting

confidence: 82%

mentioning

confidence: 99%

Expression of 1-Aminocyclopropane-1-Carboxylate Oxidase during Leaf Ontogeny in White Clover1

et al. 1999

View full text Add to dashboard Cite

show abstract

“…These features presumably derive from the iron-bound NO and endogenous amino acid ligands. The latter are very likely His residues found in the His-Xaa-Asp-(Xaa) 53-57-His sequence conserved among ACCOs and also for related iron enzymes such as isopenicillin N synthase (IPNS) and deacetoxycephalosporin C synthase (DAOCS) (33)(34)(35). IPNS and DAOCS have been characterized by x-ray crystallography, and their Fe(II) centers are found to be coordinated to the three conserved residues in this common sequence (29,36).…”

Section: Resultsmentioning

confidence: 99%

Role of the nonheme Fe(II) center in the biosynthesis of the plant hormone ethylene

Rocklin

Tierney

Kofman

et al. 1999

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

111

112

View full text Add to dashboard Cite

The final step of ethylene biosynthesis in plants is catalyzed by the enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACCO). In addition to ACC, Fe(II), O 2 , CO 2 , and ascorbate are required for in vitro enzyme activity. Direct evidence for the role of the Fe(II) center in the recombinant avocado ACCO has now been obtained through formation of enzyme⅐(substrate or cofactor)⅐NO complexes. These NO adducts convert the normally EPR-silent ACCO complexes into EPR-active species with structural properties similar to those of the corresponding O 2 complexes. It is shown here that the ternary Fe(II)ACCO⅐ACC⅐NO complex is readily formed, but no Fe(II)ACCO⅐ascorbate⅐NO complex could be observed, suggesting that ascorbate and NO are mutually exclusive in the active site. The binding modes of ACC and the structural analog alanine specifically labeled with 15 N or 17 O were examined by using Q-band electron nuclear double resonance (ENDOR). The data indicate that these molecules bind directly to the iron through both the ␣-amino and ␣-carboxylate groups. These observations are inconsistent with the currently favored mechanism for ACCO, in which it is proposed that both ascorbate and O 2 bind to the iron as a step in O 2 activation. We propose a different mechanism in which the iron serves instead to simultaneously bind ACC and O 2 , thereby fixing their relative orientations and promoting electron transfer between them to initiate catalysis.

show abstract

“…1 have been purified to homogeneity [20,26,31,67,87 ]. ACC synthase however has only partially been purified because of its low abundance and lability [46].…”

Section: Introductionmentioning

confidence: 99%