PsaC | PSI positive control/quantitation standard

• Background:

  PsaC is a conserved, chloroplast-encoded, Fe-S binding protein of approximately 10kDa, present in all known Photosystem I complexes. It is located on the stromal side of the thylacoid membranes. PsaC coordinates the Fe–S clusters FA and FB through two cysteine-rich domains.This product is a recombinant protein standard, source: Synechocystis PCC 6803.The PsaC protein standard can be used in combination with global anti-PsaC antibodies to quantitate PsaC from a wide range of species. Global antibodies are raised against highly conserved amino acid sequences in the PsaC protein.Quantitative western blot: detailed method description, video tutorial

• HS Code:

  38221900

• Applications:

  Western blot (WB)

• Field of Research:

  Photosynthesis protein standards-quantitation

• Dilution:

  Positive control: a 2 μL load per well is optimal for most chemiluminescent detection systems. Standard curve: 3 loads are recommended (eg. 0.5, 2 and 4 μL) . For most applications a sample load of 0.2 μg of chlorophyll will give a PsaC signal in this range. Exact loads can vary with the sensitivity of your system and the abundance of the target protein in your samples. Note: Optimal quantitation is achieved using moderate sample loads/well, generally 1 to 5 ug total protein.A trial experiment may be required i) to bring your sample load within the standard curve range and ii) to obtain a signal that is strong enough to reliably quantify but not so strong as to consume ECL reagents too quickly or saturate your detection system. These goals may achieved by adjusting both sample and standard loads.

• Format:

  Lyophilized in glycerol.

• Reconstitution:

  For reconstitution add 95 µl of sterile water. Note that due to glycerol in buffer, the lyophilized product appears as a dense liquid rather than a powder. Allow the product several minutes to solubilize after adding water. Mix thoroughly but gently. Avoid vigorous vortexing, as buffer contains detergent. Upon reconstitution, this standard is ready-to-load and does not require any additions or heating. See additional Handling Instructions below. PsaC standard protein concentration: 0.10 pmol/µl.

• Molecular Weight:

  11.5 kDa (larger than native protein due to the addition of His-tag), In most gels PsaC migrates between 9 and 14 kDa

• Precautions:

  Protein standard buffer composition:Protein standard buffer composition: Glycerol 10%, Tris Base 141 mM, Tris HCl 106 mM, LDS 2%, EDTA 0.51 mM, SERVA® Blue G250 0.22 mM, Phenol Red 0.175 mM, pH 8.5, 0.1mg/mL PefaBloc protease inhibitor (Roche), 50mM DTT.

• Additionnal Information:

  Handling Instructions*IMPORTANT: In our experience, viscous liquids are surprisingly stable; insufficient mixing is the most common reason for unsatisfactory results. Following mixing, briefly pulse in a microcentrifuge to collect material from cap.Standard needs to be fully thawed and thoroughly mixed before each use. Proteins tend to stratify with the more dense layer after freezing. We recommend bringing the product to room temperature and either mixing by inverting or flicking tube 5-10 times. Pipetting up and down may also provide sufficient mixing, provided the tip is moved within the tube while taking up and expelling the liquid.

• References & Citations:

  Pipitone et al. (2021) . A multifaceted analysis reveals two distinct phases of chloroplast biogenesis during de-etiolation in Arabidopsis. Elife. 2021 Feb 25;10:e62709. doi: 10.7554/eLife.62709. PMID: 33629953; PMCID: PMC7906606.Rogowski et al. (2021) Light as a substrate: migration of LHCII antennas in extended Michaelis-Menten model for PSI kinetics. J Photochem Photobiol B. 2021 Dec;225:112336. doi: 10.1016/j.jphotobiol.2021.112336. Epub 2021 Oct 19. PMID: 34736069.Levitan et al. (2019) . Structural and functional analyses of photosystem II in the marine diatom Phaeodactylum tricornutum. Proc Natl Acad Sci U S A. 2019 Aug 27;116 (35) :17316-17322. doi: 10.1073/pnas.1906726116.Li et al. (2016) . A Hard Day's Night: Diatoms Continue Recycling Photosystem II in the Dark. Front. Mar. Sci., 08 November 2016 | http://dx.doi.org/10.3389/fmars.2016.00218Vandenhecke et al. (2015) . Changes in the Rubisco to photosystem ratio dominates photoacclimation across phytoplankton taxa. Photosynth Res. 2015 Apr 11.

• Storage Conditions:

  Store lyophilized/reconstituted at -20°C; once reconstituted make aliquots to avoid repeated freeze-thaw cycles. Please remember to spin the tubes briefly prior to opening them to avoid any losses that might occur from material adhering to the cap or sides of the tube.

• CAS Number:

  9007-83-4