Human PSD3 blocking peptide

The micropropagation of apple (Malus domestica [L.] Borkh) cultivars is usually achieved by axillary bud stimulation and requires an exogenous cytokinin supply. Two cDNA libraries were constructed from mRNA isolated from plantlets grown in vitro on medium with or without benzyladenine. One cDNA clone (pSD3), corresponding to transcripts more abundant in plantlets grown on medium containing cytokinin than on medium lacking the hormone, was isolated. It corresponds to a mRNA of about 1,800 nucleotides which codes for a proline-rich protein with a predicted mass of 31,000 daltons. Its accumulation is restricted to roots and stems of in vivo grown apple plantlets and to stems of microcuttings cultivated on medium without cytokinin. Furthermore, it accumulates to comparable levels in leaves and stems when plantlets are grown on medium containing benzyladenine. A second cDNA clone (pSD4), corresponding to transcripts down-regulated in the presence of cytokinin in the culture medium, was also characterized. Its corresponding mRNA is about 700 nucleotides in length and encodes a protein highly homologous to the precursor of the 10-kilodalton polypeptide of the photosystem II from spinach. This mRNA accumulates specifically in leaves of apple plantlets and is more abundant in leaves of plantlets grown in the absence of cytokinin compared with plantlets grown in the presence of benzyladenine.

The present study aims at developing a simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of pantoprazole sodium (PS) in human plasma using pantoprazole D3 (PSD3) as internal standard (IS). Chromatographic separation was performed on Zorbax SB-C18, 4.6 mm x 75 mm, 3 5 mu m, 80 angstrom column with an isocratic mobile phase composed of 10 mM ammonium acetate (pH 7 10) acetonitrile (30 70, v/v), pumped at 06 mL/min PS and PSD3 were detected with proton adducts at m/z 384 2 -> 200 1 and 387.1 -> 203 1 in multiple reaction monitoring (MRM) positive mode. respectively Precipitation method was employed in the extraction of PS and PSD3 from the biological matrix This method was validated over a linear concentration range of 10 00-3000 00 ng/mL with correlation coefficient (r) >= 0 9997. Intra- and inter-day precision of PS were found to be within the range of 1 13-1.54 and 1.76-2 86, respectively Both analytes were stable throughout freeze/thaw cycles, bench top and postoperative stability studies. This method was successfully utilized in the analysis of blood samples following oral administration of PS (40 mg) in healthy human volunteers (C) 2010 Elsevier B V All rights reserved.