PDQuest-generated master gel image showing the general spot pattern of matched protein spots from the total leaf proteome of healthy or Las-infected lemon plants.

<p>Labeled spots were differentially produced in response to Las-infection and described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067442#tab1" target="_blank">Table 1</a>. A sum of 200 µg of total protein was separated according to charge on a pH 4-7 IpG strip and according to mass on 8-16% gradient SDS-polyacrylamide Tris-HCl gels. Protein spots were visualized by staining with Coomassie Brilliant Blue (CBB). <i>M</i>_r, relative molecular mass; pI, isoelectric point.</p

Categorization of differentially produced proteins in lemon plants in response to Las infection.

<p>(A) Venn diagram showing the number of protein spots that showed higher-accumulation (▲) or lower-accumulation (▼) in infected lemon plants compared to healthy plants. (B) Functional category distribution of differentially produced protein spots from comparing 2-DE gel images of the total leaf proteome of healthy or Las-infected lemon plants.</p

The leaf-nutrient concentrations of healthy or Las-infected lemon plants.

<p> (A) Macronutrients: calcium (Ca), potassium (K) and magnesium (Mg); (B) Micronutrients: iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu). Two-year old healthy plants were either graft-inoculated or uninoculated with PCR-confirmed Las-infected bud sticks and leaf samples were analyzed 6 months post-inoculation. Bars within a plant group with the same lower case letter are not significantly different from each other (<i>P</i> > 0.05).</p

Differentially produced protein spots from 2-DE analysis of total leaf proteins from healthy or Las-infected lemon plants.

<p>Panels A-M show magnified views of protein spots in representative 2-DE gels containing separated total proteins from leaves of healthy or Las-infected lemon plants. Labeled spots showed significant changes and correspond to the spots presented in in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067442#pone-0067442-g002" target="_blank">Figure 2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067442#tab2" target="_blank">Tables 2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067442#tab3" target="_blank">3</a>. Two-year old healthy plants were either graft-inoculated with side shoots from PCR-confirmed Las-infected bud sticks or uninoculated and leaf samples were analyzed at six months post-inoculation. A sum of 200 µg of total protein was separated according to charge on a pH 4-7 IpG strip and according to mass on 8-16% gradient SDS-polyacrylamide Tris-HCl gels. Protein spots were visualized by staining with Coomassie Brilliant Blue (CBB). <i>M</i>_r, relative molecular mass; pI, isoelectric point.</p

Quantifying Protein–Ligand Interactions by Direct Electrospray Ionization-MS Analysis: Evidence of Nonuniform Response Factors Induced by High Molecular Weight Molecules and Complexes

The deleterious effects of high molecular weight (MW) solute (polymers and noncovalent assemblies) on protein–ligand (PL) affinity measurements carried out using the direct electrospray ionization mass spectrometry (ESI-MS) assay are described. The presence of high MW solute, that do not interact with the protein (P) or ligand (L) of interest, is shown to result in a decrease in the abundance (Ab) ratio (<i>R</i>) of ligand-bound to free protein ions (i.e., Ab­(PL)/Ab­(P)) measured for protein–carbohydrate complexes. This effect, which can reduce the apparent association constant by more than 60%, is found to be more pronounced as the differences in the surface properties of P and PL become more significant. It is proposed that the decrease in <i>R</i> reflects a reduction in the number of available surface sites in the ESI droplets upon introduction of large solute and increased competition between P and the more hydrophilic PL for these sites. That a similar decrease in <i>R</i> is observed upon introduction of surfactants to solution provides qualitative support for this hypothesis

Additional file 1: Appendix 1. of Proteomics analysis reveals novel host molecular mechanisms associated with thermotherapy of ‘Ca. Liberibacter asiaticus’-infected citrus plants

Mascot match results and peptide sequences of the 130 differentially-expressed spots presented in Fig. 3. (XLSX 3295 kb

Poly(alkyl ethylene phosphonate)s: A New Class of Non-amide Kinetic Hydrate Inhibitor Polymers

All commercial kinetic hydrate inhibitor (KHI) formulations are based on polymers with amide (or imide) functional groups. In our continuing work to explore non-amide-based KHI polymers, a series of poly­(alkyl ethylene phosphonate)­s (PPns) has been synthesized. These polymers were investigated for their performance as KHIs in high-pressure rocking cells using a structure-II-forming gas mixture and the slow constant cooling test method over 24 h. All of the PPns gave better KHI activity than tests with no additive. However, despite several of the polymers being designed to have low cloud points, a factor that is often useful for good KHI performance, none of the PPns gave lower onset temperatures than poly­(<i>N</i>-vinylcaprolactam), a well-known commercial KHI with a low cloud point. A random PPn copolymer with eight ethyl and eight <i>n</i>-hexyl groups gave a biodegradation of about 31% using the marine OECD 306 test protocol

CpLEPA Is Critical for Chloroplast Protein Synthesis Under Suboptimal Conditions in <em>Arabidopsis thaliana</em>

<div><p>LEPA is one of the most conserved translation factors and is found from bacteria to higher plants. However, the physiological function of the chloroplast LEPA homolog in higher plants remains unknown. Herein, we demonstrate the physiological role of cpLEPA in enabling efficient photosynthesis in higher plants. The <em>cplepa-1</em> mutant displays slightly high chlorophyll fluorescence and pale green phenotypes under normal growth conditions. The growth of the <em>cplepa-1</em> mutant is reduced when grown on soil, and greater reduction is observed under intense light illumination. Photosynthetic activity is impaired in the <em>cplepa-1</em> mutants, which is reflected in the decreased steady-state levels of chloroplast proteins. <em>In vivo</em> protein labeling experiments explained the decrease in the steady-state levels of chloroplast proteins. An abnormal association of the chloroplast-encoded mRNAs with ribosomes suggests that the protein synthesis deficiencies in <em>cplepa-1</em> are due to defects in translation initiation in the chloroplasts. The cpLEPA protein appears to be an essential translation factor that promotes the efficiency of chloroplast protein synthesis.</p> </div

CpLEPA Protein Sequence Alignment.

<p>The amino acid sequence of cpLEPA was compared with the sequences of homologous proteins from mitochondria in <i>Arabidopsis</i>, <i>Oryza sativa, Glycine max, Physcomitrella patens</i>, <i>Hordeum vulgare, Micromonas pusilla, Synechococcus, Microcystis aeruginosa,</i> and <i>Bacillus cereus</i>. The black boxes indicate strictly conserved amino acids, and the gray boxes indicate closely related residues. The predicted chloroplast transmembrane peptides are underlined in green, The LEPA domains are underlined in red, and the LEPA-II domain is underlined in blue. LEPA-C is underlined in purple, and the CTD is underlined in yellow.</p