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Ouellette, Anthony J. A.; Barry, Bridgette A.

doi:10.1023/a:1016132700844

Cited by 20 publications

(13 citation statements)

References 29 publications

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“…PSII-3 samples (35 nmol) were incubated with 56 M 14 C-or 12 C-phenylhydrazine, 56 M 2-Brphenylhydrazine, or no phenylhydrazine under room light for 30 min in buffer containing 50 mM Hepes-NaOH, pH 7.5͞52 mM Na 2 CO 3 ͞2.6 M urea͞2% SDS (15). Samples were subjected to SDS͞PAGE, and the portion of the gel, containing CP43 and CP47, was excised (20).…”

Section: ϫ2mentioning

confidence: 99%

“…The peptides were extracted from the gel pieces, as described (20), except that 0.3% TEAA (triethylammonium acetate), pH 7.0, and acetonitrile were used in a 1:1 ratio. The peptide solution was concentrated with argon or dried in vacuo.…”

Section: ϫ2mentioning

confidence: 99%

“…Microcapillary columns containing reverse-phase packing material were constructed as described (20). The column was equilibrated with aqueous 0.2% acetic acid and 2% acetonitrile (solvent A) before injecting the sample.…”

Section: ϫ2mentioning

confidence: 99%

“…MS͞MS has been used previously to obtain structural information about intrinsic membrane proteins (for examples, see refs. [17][18][19][20]. MS is one of the few techniques that can detect altered amino acid side chains in membrane proteins, which are difficult to study by other high resolution structural techniques.…”

mentioning

confidence: 99%

“…In situ trypsin digestion of spinach PSII was performed by a previously described procedure (20). Briefly, 1.1 nmol of oxygen evolving PSII or PSII-3 was illuminated (3620 E s Ϫ1 ⅐m…”

mentioning

confidence: 99%

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Posttranslational modifications in the CP43 subunit of photosystem II

Anderson

Maderia

Ouellette

et al. 2002

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

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, and ؉18 daltons. The masses of the modifications suggest that the tryptophan is modified to kynurenine (؉4), a keto-͞ amino-͞hydroxy-(؉16) derivative, and a dihydro-hydroxy-(؉18) derivative of the indole side chain. Peptide synthesis and MS͞MS confirmed the kynurenine assignment. The ؉16 and ؉18 tryptophan modifications may be intermediates formed during the oxidative cleavage of the indole ring to give kynurenine. The sitedirected mutations, W352C, W352L, and W352A, exhibit an increased rate of photoinhibition relative to wild type. We hypothesize that Trp-352 oxidative modifications are a byproduct of PSII water-splitting or electron transfer reactions and that these modifications target PSII for turnover. As a step toward understanding the tertiary structure of this CP43 peptide, structural modeling was performed by using molecular dynamics.mass spectrometry ͉ collision-induced dissociation ͉ tryptophan ͉ kynurenine ͉ photoinhibition P hotosystem II (PSII) is a protein-pigment complex located in thylakoid membranes of plants, eukaryotic algae, and cyanobacteria. PSII catalyzes the light-driven oxidation of water to O 2 , and the reduction of plastoquinone. PSII contains both intrinsic and extrinsic polypeptides. The intrinsic polypeptides include chlorophyll-binding proteins, CP47, CP43, and the D1 and D2 polypeptides (reviewed in ref. 1). The D2͞D1 heterodimer binds P 680 , pheophytin, and the quinone receptors, Q A and Q B (2). Three extrinsic subunits, the manganese stabilizing, 24-kDa, and 18-kDa proteins, are required for maximum oxygen evolution in plants (3, 4). Recently, a 3.8-Å structure of the cyanobacterial PSII reaction center has been reported (5, 6).The intrinsic PSII subunits, CP43 and CP47, function as light-harvesting proteins and play a role in PSII assembly and activity (7-11). CP47 and CP43 have similar tertiary and secondary structures (5). Each polypeptide has six membranespanning regions and a large luminal, hydrophilic loop (E) between helix V and VI (5, 7). In Synechocystis sp. PCC 6803, loop E of the CP43 subunit extends from residue Asn-280 to . Mutations or deletions in this loop inactivate or impair PSII activity in Synechocystis (9, 11-13).Posttranslational modifications can play important roles in the assembly, degradation, structure, and function of proteins. However, little is known about the roles of such modifications in membrane proteins. For example, in cytochrome c oxidase, a crosslinked tyrosine-histidine cofactor has been identified at the binuclear metal site (14); the function of this cofactor has not yet been definitively established. Recently, it has been suggested that posttranslationally modified amino acids, containing carbonyl groups, covalently bind hydrazines and amines at the catalytic site of PSII (10, 15). Because amines and hydrazines are inhibitors of photosynthetic water oxidation, it was suggested that these carbonyl-containing amino acids play roles in the structure, function, or assembly of PSII.To obtain more information about posttranslational mod...

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Section: ϫ2mentioning

confidence: 99%

Section: ϫ2mentioning

confidence: 99%

Section: ϫ2mentioning

confidence: 99%

mentioning

confidence: 99%

“…In situ trypsin digestion of spinach PSII was performed by a previously described procedure (20). Briefly, 1.1 nmol of oxygen evolving PSII or PSII-3 was illuminated (3620 E s Ϫ1 ⅐m…”

mentioning

confidence: 99%

See 3 more Smart Citations

Posttranslational modifications in the CP43 subunit of photosystem II

Anderson

Maderia

Ouellette

et al. 2002

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

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Intact mass measurements for unequivocal identification of hydrophobic photosynthetic photosystems I and II antenna proteins

et al. 2004

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The purpose of this study was to determine the optimal experimental conditions necessary to allow rapid and accurate identification of highly hydrophobic proteins, such as the antenna proteins from photosystems I and II. The antenna proteins were derived from two different species, tomato and Arabidopsis, whose photosynthetic genome is well known. The separation techniques included sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by immunoblotting, microamino acid sequencing, reversed-phase high-performance liquid chromatography (RP-HPLC), intact mass measurements, and peptide mass fingerprinting by mass spectrometry. Immunoblotting was time-consuming, and success was limited due to cross-reactivity between these highly conserved sequences. The best results by far were achieved by separating intact proteins through hyphenation of reversed-phase liquid chromatography on-line to an electrospray ionization mass spectrometer (ESI-MS) and consequently identifying individual proteins from their intact mass measurements (IMMs), whereas peptide mass fingerprinting was hampered by the highly hydrophobic nature of these proteins. RP-HPLC-ESI-MS was superior in the quality of separation. Moreover, the high quality of mass spectra recorded during the RP-HPLC-ESI-MS analysis meant that the relative deviations of the molecular masses determined with a quadrupole ion trap mass analyzer ranged between 100 and 300 ppm. Thus, the correspondence between the intact mass values measured with those deduced from the DNA sequences allowed the different types of antenna proteins to be identified and assigned to their corresponding gene families. By utilizing this correlation, it was possible to spot gene products of previously cloned genes.

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Current literature in Journal of Mass Spectrometry

2002

J. Mass Spectrom.

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In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (4 Weeks journals ‐ Search completed at 21st. Aug. 2002)

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Untitled

Cited by 20 publications

References 29 publications

Posttranslational modifications in the CP43 subunit of photosystem II

Posttranslational modifications in the CP43 subunit of photosystem II

Intact mass measurements for unequivocal identification of hydrophobic photosynthetic photosystems I and II antenna proteins

Current literature in Journal of Mass Spectrometry

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