The present results with the human microbiota suggest that, at le

The present results with the human microbiota suggest that, at least in the individuals who provided samples here, amino acid utilizing bacteria are more dominant than peptide utilizers. The results with faecal samples from omnivores compared to vegetarians were inconclusive in terms of NH3 production, but the ranking order of dissimilation of different amino acids was similar. The influence of monensin was different with different amino acids. Pro, Ala and Glu were inhibited most, with Asp and Lys affected only to a minor extent. Once again, the reason for this difference is unclear,

but presumably reflects the inhibition of some transport systems and not others, or possibly a differential inhibition of species that metabolize different amino acids [17, 18]. One of the principal aims of this work was to investigate if, by analogy with the rumen, HAP bacteria were present in the human colon. Conditions of low-carbohydrate, high-protein

Selumetinib mouse nutrient availability would favour bacteria able to derive energy from amino acids, particularly in the distal colon, but the general procedure of routinely adding sugars to growth media may have concealed these bacteria in culture-based studies. There had been a long-held assumption for the rumen that a large group of bacteria identified many years ago [32] was responsible for ruminal amino acid deamination. Russell and his colleagues at Cornell University challenged this assumption, and check details isolated less numerous, but much more active, asaccharolytic, obligately peptide-fermenting bacteria, the HAP ID-8 species [18]. SGC-CBP30 nmr Growth of HAP bacteria was inhibited by monensin, while the more numerous NH3 producers were unaffected, yet NH3 production by the mixed ruminal microbiota was monensin-sensitive. The present paper suggests that the human microbiota has an NH3-producing

activity about one-third that of the rumen [17]. Nevertheless, it is clear that a substantial fraction of NH3 production from peptides and amino acids is monensin-sensitive, so the possibility existed that HAP species were present in human colonic digesta. Bacteria capable of growth on peptides as energy source were variable in number, averaging 3.5% of the total viable count. This proportion is somewhat higher than was found in ruminal digesta [16–18]. Actual numbers varied from 0.8 × 107 to 3.5 × 108 (g wet wt)-1, which compares with 1011 per g dry weight on peptone medium measured by Smith & Macfarlane [1]. Numbers capable of growth on amino acids were almost as high as those growing on Trypticase, which is a complete contrast to the rumen, where numbers of amino acids utilizers were two orders of magnitude less than Trypticase utilizers [17]. Thus, the bacterial population capable of using protein breakdown products in the human colon was more numerous than in the rumen, but less active, and differed in its much lower preference for peptides.

The modified FAB medium was supplemented with glucose (100 mg l-1

The modified FAB medium was supplemented with glucose (100 mg l-1) as carbon source and isopropyl-thio-beta-galactoside (IPTG; 12 mg l-1) to ensure expression of fluorescent proteins from the PA1/04/03 promotor. The flow system was assembled and prepared as described Rabusertib previously selleck chemicals [24]. A microscope cover slip of borosilicate (Knittel 24 × 50 mm st1; Knittel Gläser) was used as substratum. The flow chambers were inoculated by injecting approximately 2 × 106 cells, into each flow chamber

with a small syringe. After inoculation, the flow chambers were left without flow for 1 h, and medium flow (0.2 or 0.8 mm s-1 corresponding to laminar flow and Re numbers of 0.3 and 1.3,

respectively) was started using a Watson Marlow 205 S peristaltic pump and the system was incubated at 30°C. Microscopy and image acquisition Biofilm formation was monitored by CLSM four, 24, 48, and 72 hours after inoculation. Microscopic observations and image acquisitions were performed with a Zeiss LSM 510 CLSM (Carl Zeiss, Jena, Germany) using a 40 ×/1.3 oil objective. Enzalutamide datasheet The microscope was equipped with lasers, detectors and filter sets for detecting CFP and YFP fluorescence. Simulated three-dimensional images were generated using the IMARIS software package (Bitplane AG, Zürich, Switzerland). Quantification of biofilm formation and statistical analysis For quantitative analysis of the biofilms, CLSM images were analysed by the computer program diglyceride COMSTAT [25]. The total amount of biomass on the surface, the relative substratum coverage

and the average thickness of the biofilm were calculated. Differences between the wild type and each mutant in the three parameters were compared by using a two-tailed independent t-test. P values below 0.05 were considered to be statistically significant. Fimbrial switch orientation assay A modification of a previously described method was used to determine the orientation of the fim-switch in K. pneumoniae biofilms [18, 26]. Biofilm samples were obtained by aspiration of the biofilm from individual flow cell channels by use of a syringe. All inoculum and biofilm samples were boiled for 5 min in PBS immediately after collection and then kept at -20°C until use. After thawing, the samples were boiled for 5 min, centrifuged at 12,000 g for 15 min and 2 μl of the supernatant used as template for PCR. Primers CAS168 and CAS169 (Table 1) were used to amplify an 817 bp region containing the fim-switch by use of the Expand High Fidelity PCR System (Roche).

We contend

that the beneficial effects of CR

We contend

that the beneficial effects of CR supplementation on muscle strength and weightlifting performance AZD2014 molecular weight during resistance selleck training are largely the result of the CR-loaded subjects ability to train at a higher workload than placebo-supplemented subjects, as suggested previously [27, 28]. However, while this may be the case when maintaining rest interval length, our present data indicate that when rest interval length is decreased significantly, the total training load is decreased despite CR supplementation. Although we did not include a true control group that did not receive CR supplementation but underwent training using a progressively decreasing rest interval; it is plausible that CR may attenuate the decrease in training volume when VS-4718 concentration subjects are exposed to such a condition. Regardless, and perhaps of most importance to athletes who use CR for purposes of increasing strength and muscle mass, the volume of training was greater for the CI group versus the DI group but strength gains were similar between groups. Thus, the creatine

supplementation appeared to bolster strength gains particularly for the DI group, even in the presence of significantly less volume. However, future work is needed to investigate the relationship between CR supplementation versus no supplementation on volume parameters and strength and muscle mass increases during long term studies. In long-term studies, subjects taking CR typically gain about twice as much body mass and/or fat free mass (i.e., an extra 2 to 4 pounds of muscle mass during 4 to 12 weeks of training) versus subjects taking a placebo [29, 30]. The gains in muscle mass appear to be a result of an improved

ability to perform high-intensity exercise via increased PCR availability and enhanced ATP synthesis, thereby enabling an athlete to train harder to promote greater muscular hypertrophy ID-8 via increased myosin heavy chain expression; possibly due to an increase in myogenic regulatory factors myogenin and MRF-4 [31–33]. In the present study, we clearly noted a reduction in training volume for the DI group. We speculate that because the loads for the current study were in the 8-10 RM range, perhaps anaerobic glycolysis was being emphasized to a greater extent for ATP production. As the rest intervals were progressively shorter in the DI group, there would have been limited time to resynthesize PCr, and greater reliance would have been placed on rapid glycolysis to effectively meet energy demands. Therefore, creatine supplementation might be more effective in maintaining volume with higher loads and less repetitions per set (e.g. one to six repetition maximum per set). Despite this, subjects in the DI group maintained similar adaptations in muscle strength and CSA as compared to subjects in the CI group.

36 vs 0 49 mm2; F[1,8] = 72 25, p < 0 0001) However, quite unex

36 vs. 0.49 mm2; F[1,8] = 72.25, p < 0.0001). However, quite unexpectedly, the Stf- phage made a smaller plaque when plated on the ΔOmpC host, as opposed to the wt host (0.75 vs. 1.26 mm2; F[1,8] = 14.98, p = 0.005). For expectation (ii), we observed that, when plated on the wt host, the Stf+ phage made a smaller plaque when compared to the Stf- BX-795 phage (0.36 vs. 1.26 mm2; F[1,8] = 232.07, p < 0.0001). However, when plated on the ΔOmpC host, we only observed a borderline significant level of plaque size difference between the Stf+ and Stf- phages (0.49 vs. 0.75 mm2; F[1,8] = 4.45, p = 0.068; however, the non-parametric Wilcoxon/Kruskal-Wallis

test showed a significant difference, z = -2.01, p = 0.034 for the one-way test). For expectation (iii), we observed that the plaque size difference between the Stf+ and Stf- phages is significantly larger when plated on the wt host (3.5-fold, with 95% confidence Selleck LY2835219 interval of 3.15 – 3.92-fold vs. 1.5-fold, with 95% confidence interval of 0.95 – 2.10-fold), indicating that a larger virion, as a result of having extra appendages, would retard virion diffusion through the top agar layer, thus reducing the plaque size. Figure

3 Effecs of host type and Stf on plaque size. Plaque sizes were determined for the Stf+ (filled circles) and Stf- (open circles) by plating on either the witld type (wt) or the ΔompC (ΔOmpC) E. coli cells. Error bars showed the 95% confidence intervals. Horizontal solid lines intend to show the size differences from the same phages when plated on different host. Testing model predictions

on phage plaque size and productivity Abedon and Culler [16, 22] reviewed seven mathematical models on phage plaque enlargement, as listed in the Appendix. Unfortunately, these models cannot be tested directly with our current data. This is because all the models required the parameter of virion diffusivity, a quantity we did not measure in this study. However, by taking advantage of our identical experimental condition and various isogenic phage strains that only differed Dichloromethane dehalogenase in selected traits, we can nevertheless test the relative impacts of various phage traits on plaque formation and progeny production in the plaques. We reasoned that the plaque radius r or plaque productivity p can be expressed as functions of phage traits so that r = f(a, L, D) and p = g(a, L, D), where a is the adsorption rate, L the lysis time, and D the phage diffusivity. For isogenic phage strains that only differ in adsorption rates, the expected ratios of r 1 /r 2 and p 1 /p 2 can be simplified as r 1 /r 2 = f(a 1 , L, D)/f(a 2 , L, D) = f(a 1 )/f(a 2 ) and p 1 /p 2 = g(a 1 , L, D)/g(a 2 , L, D) = g(a 1 )/g(a 2 ).

The mAb titer was determined

The mAb titer was determined Enzalutamide cost by indirect ELISA as described above and Ig subtypes of them were determined using the Mouse MonoAb-ID Kit (HRP) (Invitrogen, Carlsbad, CA, USA) according to the manufacturer’s instructions. This test identified IgG1, IgG2a, IgG2b, IgG3, IgA and IgM subtype classes, while κ and λ light Lazertinib cost chains were determined using monospecific rabbit polyclonal antibodies (Pabs). Determination

of epitopes by phage-displayed random peptide library The Ph.D.-12™ Phage Display Peptide Library Kit was purchased from New England BioLabs Inc.. The dodecapeptide library consists of 2.7 × 109 electroporated sequences (1.5 × 1013 pfu ml-1). All mAbs were purified from ascites of mice inoculated with the hybridoma cells secreting antibody

by affinity chromatography using rProtein G (Sigma, find more USA) according to the manufacturer’s instructions, and the concentration of purified antibody was determined by the Bradford Protein Assay Kit (http://​www.​beyotime.​com/​CompatibilityCha​rtForBradfordKit​.​Pdf). Three successive rounds of biopanning were carried out according to the manufacturer’s instruction manual. Briefly, one well of a 96-well microtiter plate was coated with 15 μg of purified mAb in coating buffer (0.1 M NaHCO3, pH 8.6), followed by blocking with blocking buffer (0.1 M NaHCO3, pH 8.6 and 5 mg ml-1 BSA) for 2 h at 4°C. About 1.5 × 1011 pfu (4 × 1010 phages, 10 μl of the original library) were added to the well and incubated for 1 h at room temperature by gentle shaking. Unbound phages were removed by successive washings with TBS buffer (50 mM Tris-HCl, pH 7.5; 150 mM NaCl) containing gradually increased concentrations (0.1%, 0.3%, and 0.5%) of Tween-20, and bound phages were eluted with elution buffer (0.2 M Glycine-HCl, pH 2.2) containing 1 mg ml-1 BSA. The eluted phages were amplified in early-log E. coli ER2738 strain

cells. After three rounds of biopanning, ten individual phage clones were selected and assayed second for target binding by sandwich ELISA as described by the manufacturer’s instructions. Briefly, 96-well microtiter plates were coated overnight with 2 μg of mAb or irrelevant control mAb (anti-porcine IFN-γ mAb, Sigma, USA). After 2 h of blocking with blocking buffer at 4°C, phage clones were added to the wells (2 × 1011 pfu in 100 μl per well) and incubated with agitation for 2 h at room temperature. Bound phages were subjected to reaction with HRP-conjugated anti-M13 antibody (Pharmacia, USA) for 2 h at room temperature, followed by color development with substrate solution containing o-phenylenediamine (OPD). The DNA inserts displayed by ELISA-positive phage clones were sequenced with the 96 gIII sequencing primer: 5′-TGAGCGGATAACAATTTCAC-3′ as described by the manufacturer’s instructions (New England BioLabs Inc.).


Post hoc one-way ANOVA for repeated measures showed


Post hoc one-way ANOVA for repeated measures showed MP produced Sapanisertib during sprints four and five with GPLC were significantly greater than the values produced with PL (p’s < 0.05). Power Decrement Figure 3 displays the DEC values during both test conditions. As previously mentioned, DEC increased significantly with ongoing sprint bouts. However, analysis of the DEC data did not reveal significant effects find more of GPLC (p = 0.65) or significant interaction with sprint bouts (p = 0.51). Interestingly, the difference between conditions in mean values of DEC tended to increase as sprint bouts progressed with a statistically significant difference (p < 0.05) in the fifth sprint with a 38% power decrement with PL while GPLC produced a 41.3% rate of power decrement. Relative total power decrement within each test session for PP was lower with GPLC than PL, with 26.6% and 32.8% declines in those values respectively, however this difference was not statistically significant (p = 0.09). The mean MP total power decrement values were not statistically different between groups (p = 0.32) with 36.4% and 33.1% for GPLC and PL, respectively. Lactate A significant main effect for condition was observed for lactate measures (p < Epacadostat mouse 0.05). Figure 4 displays the lactate measures at rest as well as four and 14 minutes

post-exercise. There were no significant differences between conditions in lactate levels at rest. Lactate measures taken at four and fourteen minutes post-exercise Y-27632 2HCl were 15.6% and 16.2% lower, respectively, with GPLC. Paired timepoint analyses

indicated that the differences between conditions were statistically significant at 14 minutes post-exercise (p < 0.05) but not four minutes following the sprint bouts (p = 0.09). Net lactate accumulation per unit power output, calculated as (LAC14-LACrest). (MPave)-1 differed significantly between conditions (p < 0.05). GPLC produced 22.8% less net lactate per watt than placebo, 0.947 and 1.227 mmol. watt-1, respectively Heart rate Heart rate was recorded at rest, during the final 10 seconds of each sprint bout, as well as 4 and 14 minutes post-exercise (see Figure 5). There were no significant effects of condition or interaction effects detected for values of HR. As previously mentioned, HR tended to increase across time with a considerable increase in HR from rest to bout 1, then slightly increasing with subsequent sprint bouts to peak values of approximately 169 bpm in both conditions. Post-exercise HR responses did not differ appreciably between the GPLC and PL conditions with values of approximately 130 and 111 bpm at four and 14 minutes, respectively, following the sprints. Thigh girth There were no significant main condition effects or condition × time interactions in the measures of thigh girth. There was a significant main effect of time (pre-, post-exercise) indicating similar increases in thigh girth in both conditions (GPLC, PL). Girth increased from 57.1 ± 6.0 to 58.9 ± 6.

References 1 Kleiner HE, Krishnan P, Tubbs J, Smith M, Meschonat

References 1. Kleiner HE, Krishnan P, Tubbs J, Smith M, Meschonat C, Shi R, Lowery-Nordberg M, Adegboyega P, Unger M, Cardelli J, et al.: Tissue microarray analysis of eIF4E and its downstream effector proteins in human breast cancer. J Exp Clin Cancer Res 2009, 28: 5.CrossRefPubMed”
“Background Electric field is a new biomedical engineering technique which can be used as electrochemotherapy, tumor ablation, or intracellular

electromanipulation respectively [1, 2]. The biological basis of electrohemotherapy is the combination of reversible AZD6244 membrane electroporation caused by weak intensity microsecond electric pulse and subsequent enhanced intracellular drug-uptake such as bleomycin and cisplatin for their cytotoxicity [3]. Alternatively, distinct from electrochemotherapy,

irreversible membrane electroporation induced by intensive energy microsecond electric pulse can be used alone to implement tumor ablation directly without any cytotoxic drugs [4–6]. Furthermore, different from microsecond electric pulse, nanosecond electric pulse decreases its selleck kinase inhibitor effect on plasma membrane and imposes electric force on multiple subcellular structures known as intracellular electromanipulation, which can be used in cancer treatment, gene Stattic manufacturer therapy and wound healing [7]. Therefore, electric field possesses parameters related different biophysical effects. However, to the best of our knowledge, few researchers have involved any information about the biophysical selleck products effects regarding the combined application of

microsecond and nanosecond duration electric pulse in cancer treatment. Our group has dedicated to investigate antitumor effects of SPEF for many years. The distinct characteristic of this exponential decayed SPEF was that the rising period was shortened to the nanosecond level which contains abundant high frequency electromagnetic components (we call it steep pulsed electric fields), and the descending period remained in the microsecond level which contains lots of low frequency electromagnetic components [8]. Therefore, this specially designed SPEF composed of a dual component type of pulse, which different from microsecond duration, low repetition frequency electric fields typically used in electrochemotherapy. For the first time, we confirmed that the combined effect of micro- and nano-second electric pulse contained in SPEF could destroy cancer cells effectively through reversible or irreversible membrane electroporation [8–12] or trigger various biophysical responses within caner cells [13]. Furthermore, the killing effect of SPEF depended on pulse parameters, excessive electric field intensity could cause extra damage to surrounding normal tissue [14].

The absence of genes encoding putative desaturases in the Ivo14T

rubra either does not use desaturases for the synthesis of unsaturated fatty acids or the oxygen-independent de novo synthesis leads to the common 18:1 ω7 and 16:1 ω7 Selleckchem CHIR98014 fatty acids. In this

way harmful reactive oxygen species are inactivated by the directed oxidation of saturated fatty acid chains within the cytoplasmic membrane. Thus, strains like C. litoralis DSM 17192T or Chromatocurvus halotolerans DSM 23344T may be better adapted to oxidative stress than Ivo14T, which would explain that the negative effect of light on pigment production is most pronounced in strain Ivo14T[32]. In a recent study it was shown that in Dinoroseobacter shibae the repression of pigment synthesis is mainly caused by oxidative stress [36]. Table 2

selleck chemicals llc Cellular fatty acid patterns of the novel isolate Ivo14 T and some related members of the OM60/NOR5 clade Fatty acid 1 2 3 4 5 6 Saturated fatty acids   10:0 ― ― ― ― ― 0.9   11:0 0.6 ― 1.0 ― 0.8 1.6   12:0 5.0 1.0 2.2 1.1 2.3 1.1   13:0 ― 0.9 1.0 ― 1.2 1.3   14:0 5.4 0.7 2.0 1.8 2.3 2.2   15:0 4.2 7.4 4.9 1.0 4.5 6.6   15:0 ISO ― ― ― ― 0.6 ―   16:0 24.0 8.1 5.4 26.8 5.7 11.7   17:0 3.1 5.2 3.1 0.7 5.8 7.0   18:0 ― ― 0.6 0.6 ― ― Unsaturated fatty acids   15:1 ω6c ― 1.8 2.0 ― 4.0 1.1   15:1 ω8c ― 1.3 ― ― 0.8 2.7   16:1 ω6c ― ― 6.5 ― ― ―   16:1 ω7c 36.1 21.3 23.1 24.4 26.5 18.3   17:1 ω6c ― 5.6 2.8 ― 2.3 3.6   17:1 ω8c ― 19.2 8.1 0.7 15.4 15.3   18:1 ω7c 9.7 18.0 29.7 30.0 19.3 19.3   19:1 cyc ω8c

― ― ― ― 0.7 ― Hydroxy fatty acids   10:0 3OH 4.8 0.9 2.1 ― 2.4 0.8   11:0 3OH 0.6 1.2 ― ― 2.5 2.0   12:0 2OH ― ― ― 1.0 ― ―   12:0 3OH 2.2 1.1 ― ― 1.6 1.3   12:1 3OH ― 1.5 ― 2.4 ― ―   13:0 3OH 0.7 ― ― ― ― ― Sum in Feature 7 1.3 0.8 2.8 ― ― ― Biomass was obtained by growth of cells on Marine Agar 2216 under fully aerobic conditions. Values are percentages of total fatty acids. Major fatty acids (>5% DOCK10 of total amount) are given in bold. Fatty acids that were detected only in trace amounts (0.5% or less of the total amount) are not shown. The find more position of the double bond in unsaturated fatty acids is located by counting from the methyl (Ω) end of the carbon chain; cis isomers are indicated by the suffix c; ISO indicates iso-branched fatty acids. Summed feature 7 contained one or more of the following fatty acids that could not be separated by GLC with the MIDI system: 19:1 ω6c, 19:0 cyc and an unknown fatty acid with an equivalent chain length of 18.846.

Downregulation of HSP60 was found in prostate cancer[34]and lung

Downregulation of HSP60 was found in prostate cancer[34]and lung cancer[35]. Positive HSP60 expression in esophageal squamous cell carcinoma[36], ovarian cancer [37] and bladder cancer[38] correlated with good prognosis for the patients. Mechanistic studies in different cell models indicated that association of HSP60 with procaspase-3 promotes caspase-3 maturation and activation, suggesting a pro-apoptotic role[32, PHA-848125 cost 39, 40]. In the past decades, regarding HSP60′s roles in CRC, most of the data come from expression observations. As shown

by immunohistochemistry, western blot[41–43] and by cDNA microarray analysis[44, 45], it was found that HSP60 was overexpressed in CRC tissue. The levels of HSP60 correlated with tumor grade and stage and with occurrence

of lymph node metastases[44]. While the data on the exact biological function of HSP60 in CRC cells is still lack. In this study, to clarify the biological role of the down-regulation of HSP60 induced by IGFBP7, we also explored the function of HSP60 protein in PcDNA3.1(IGFBP7)RKO cells. We found that addition of recombinant HSP60 could increase the proliferation rate and increase the colony formation ability of PcDNA3.1(IGFBP7)-RKO Bortezomib in vivo cells. The studies provide the evidence that 1. HSP60 protein may be a key molecule enrolled in CRC initiation and progression. 2. Downregulation of HSP60 may participate in, at least in part, the growth inhibiting role of IGFBP7 on colon cancer cells. However, the exact underlying molecular mechanism is still unclear. Both IGFBP7 and HSP60 could influence the extracellular signal pathways. Wajapeyee

et al. CA-4948 chemical structure reported that secretion of IGFBP7 acted through autocrine/paracrine pathways to inhibit mitogen-activated protein kinase (MAPK)- extracellular signal -regulated kinase (ERK) signaling [46]. Zhang et al. reported that HSP60 protected epithelial cells from stress-induced death through activation of ERK and inhibition of caspase 3 [47]. Whether HSP60 is complexed with pro-caspase 3 and influenced the caspase 3 and ERK signaling in colon cancer cells will remain an active subject of our ongoing research. Conclusion We have identified six candidate proteins whose expression were downregulated Carnitine palmitoyltransferase II by reintroduction of IGFBP7 in the colon cancer RKO cells using a proteomics approach. These results contributed to our better understanding of the potential underlying molecular mechanism for IGFBP7′s tumor suppressive role in CRC. Downregulation of HSP60 may be responsible for, at least in part, the proliferation inhibiting role of IGFBP7 in colorectal cancer cells. Further studies are warranted to elaborate the exact biological role and the molecular mechanism for HSP60 in colorectal carcinogenesis. Acknowledgements We thank the Research Center for Proteome Analysis, the Institute of Biochemistry and Cell Biology, the Shanghai Institute for Biological Science, and the Chinese Academy of Sciences for helping in MS analysis.

2004) Either the standard or modified assay described above coul

2004). Either the standard or modified assay described above could be used as a two-stage assay. To demonstrate this fact, RCA activity was measured in two stages using a timed assay to determine the suitability of the dPGM-linked

reaction sequence for automation. In the first stage, Rubisco in the ER form was incubated with RuBP, ATP and RCA before heating at 95 °C. The 3-PGA produced during the first stage was then determined by adding an aliquot of the reaction to a second stage assay that converted 3-PGA to lactic acid (Fig. 1b). The data showed that it was possible to measure activation of the ER form of Rubisco by RCA using this two-stage assay with a single time point (Supplemental Table S3). Discussion The interaction of Rubisco and RCA The physical interaction between RCA and #learn more randurls[1|1|,|CHEM1|]# Rubisco has long been enigmatic, presumably because of the transient nature of the binary complex. Rubisco and RCA do not form a stable binary complex that would facilitate a thorough characterisation of the molecular details of the interaction (Portis et al. 2008; Blayney et al. 2011). However, the consequence

of the interaction can BAY 11-7082 supplier easily be detected by measuring the effect of RCA on Rubisco activity (Salvucci et al. 1985). In the presence of ATP, RCA increases the activity of inhibited forms of Rubisco, i.e., forms produced by the tight binding

of certain sugar-phosphates Sodium butyrate (Portis 2003), including the unproductive binding of the substrate, RuBP, to uncarbamylated enzyme. Wang and Portis (1992) showed that the increases in Rubisco activity that resulted from the productive interaction of ER with RCA were associated with more rapid dissociation of inhibitory sugar-phosphates. These data indicate that “activation of Rubisco” by RCA involves altering the positions of specific domains around the Rubisco active site to allow bound sugar-phosphates to dissociate more rapidly. Although the precise nature of the interaction between RCA and Rubisco is unknown, specific residues of both Rubisco and RCA that are involved in the interaction have been identified (Ott et al. 2000; Larson et al. 1997; Li et al. 2005; Portis et al. 2008). The positions of these residues suggest some possibilities for how RCA remodels the conformation of Rubisco (Stotz et al. 2011; Henderson et al. 2011; Wachter et al. 2013). Significance of measuring RCA activity at variable ratios of ADP:ATP The effect of RCA on Rubisco activity has been investigated most often using purified proteins in a simple, timed assay that measures the incorporation of radioactive carbon from CO2 into acid-stable products. A high throughput version of this assay was even used to screen for RCA variants with increased thermotolerance (Kurek et al. 2007).