Search results for "two-dimensional"
showing 10 items of 350 documents
Phosphorylation of serine residues is fundamental for the calcium-binding ability of Orchestin, a soluble matrix protein from crustacean calcium stor…
2003
International audience; Orchestia cavimana is a terrestrial crustacean, which cyclically stores calcium in diverticula of the midgut, in the form of calcified amorphous concretions. These concretions are associated with a proteinaceous matrix, the main constituent of the soluble matrix is Orchestin, an acidic calcium-binding protein [Testenière et al., Biochem. J. 361 (2002) 327-335]. In the present paper, we clearly demonstrate that Orchestin is phosphorylated on serine and tyrosine residues, but that calcium binding only occurs via the phosphoserine residues. To our knowledge, this is the first example of an invertebrate mineralization for which a post-translational modification is clearl…
The first comprehensive and quantitative analysis of human platelet protein composition allows the comparative analysis of structural and functional …
2012
AbstractAntiplatelet treatment is of fundamental importance in combatting functions/dysfunction of platelets in the pathogenesis of cardiovascular and inflammatory diseases. Dysfunction of anucleate platelets is likely to be completely attributable to alterations in posttranslational modifications and protein expression. We therefore examined the proteome of platelets highly purified from fresh blood donations, using elaborate protocols to ensure negligible contamination by leukocytes, erythrocytes, and plasma. Using quantitative mass spectrometry, we created the first comprehensive and quantitative human platelet proteome, comprising almost 4000 unique proteins, estimated copy numbers for …
Sulfated Lupane Triterpene Derivatives and a Flavone C-Glycoside from Gypsophila repens
2007
A new sulfated lupane triterpene, Gypsophilin (1), and its glucosyl ester, Gypsophilinoside (2) were isolated from the roots of Gypsophila repens whereas a new flavone C-glycoside (3) was obtained from the aerial parts. Their structures were established as (3beta)-3-O-(sulfo)lup-20(29)-en-23,28-dioic acid (1), (3beta)-3-O-(sulfo)lup-20(29)-en-23,28-dioic acid -28-O-beta-D-glucopyranosyl ester (2) and luteolin-7-O-alpha-L-arabinopyranosyl-6-C-beta-glucopyranoside (3) by spectroscopic methods such as 1D and 2D NMR, HR-ESI-MS and FAB-MS.
Absence of regular alpha2(I) collagen chains in colon carcinoma biopsy fragments.
1998
The extracellular matrix (ECM) is known to play an active role in numerous biological processes such as differentiation, apoptosis and cancer. Extensive alterations of epithelial basement membranes and of interstitial ECM are known to occur during the progression of most invasive carcinomas. Collagen, which represents the major component of the interstitial ECM, is primarily involved in the stromal changes at the site of tumor cell invasion. We have previously described the occurrence in breast and colon cancer ECM of an oncofetal form of collagen, characterized by an acidic chain distinct from those of type I and III collagen. In the present paper, we bring evidence that alpha2(I) collagen…
Large-scale proteomic identification of S100 proteins in breast cancer tissues
2010
Abstract Background Attempts to reduce morbidity and mortality in breast cancer is based on efforts to identify novel biomarkers to support prognosis and therapeutic choices. The present study has focussed on S100 proteins as a potentially promising group of markers in cancer development and progression. One reason of interest in this family of proteins is because the majority of the S100 genes are clustered on a region of human chromosome 1q21 that is prone to genomic rearrangements. Moreover, there is increasing evidence that S100 proteins are often up-regulated in many cancers, including breast, and this is frequently associated with tumour progression. Methods Samples of breast cancer t…
Cyclic heptapeptides from the soil-derived fungus Clonostachys rosea
2019
Abstract Three new cyclic heptapeptides (1–3) together with three known compounds (4–6) were isolated from a solid rice culture of the soil-derived fungus Clonostachys rosea. Fermentation of the fungus on white beans instead of rice afforded a new γ-lactam (7) and a known γ-lactone (8) that were not detected in the former extracts. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR spectra as well as by HRESIMS data. Compounds 1 and 4 exhibited significant cytotoxicity against the L5178Y mouse lymphoma cell line with IC50 values of 4.1 and 0.1 µM, respectively. Compound 4 also displayed cytotoxicity against the A2780 human ovarian cancer cell line with an IC50…
Junceosides A-C, new triterpene saponins from Arenaria juncea.
2002
Three novel triterpenoid saponins, junceosides A (1), B (2), and C (3), together with two known saponins have been isolated from the roots of Arenaria juncea. Their structures were elucidated using a combination of homo- and heteronuclear 2D NMR techniques (COSY, TOCSY, NOESY, HSQC, and HMBC) and by FABMS. The new compounds were characterized as 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-beta-D-glucuronopyranosylgypsogenin-28-O-beta-D-glucopyranosyl(1-->3)-[beta-D-xylopyranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (1), 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-beta-D-glucuronopyranosylgypsogenin-28-O-beta-D-x…
A method for measurement of spin-spin couplings with sub-mHz precision using zero- to ultralow-field nuclear magnetic resonance.
2017
We present a method which allows for the extraction of physical quantities directly from zero- to ultralow-field nuclear magnetic resonance (ZULF NMR) data. A numerical density matrix evolution is used to simulate ZULF NMR spectra of several molecules in order to fit experimental data. The method is utilized to determine the indirect spin-spin couplings ($J$-couplings) in these, which is achieved with precision of $10^{-2}$--$10^{-4}$ Hz. The simulated and measured spectra are compared to earlier research. Agreement and precision improvement for most of the $J$-coupling estimates are achieved. The availability of an efficient, flexible fitting method for ZULF NMR enables a new generation of…
1H, 13C, 15N NMR, ESI mass spectral and single crystal X-ray structural characterization of three spiro[pyrrolidine-2,3′-oxindoles]
2006
Abstract Three spiro[pyrrolidine-2,3′-oxindoles], 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-phenyl-spiro[3H-indole-3,3′-[3H]-pyrrolizine]-2′-carboxylic acid methyl ester (1), 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-nitro-2′-phenyl-spiro[3H-indole-3, 3′-[3H]-pyrrolizine] (2) and 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-nitro-2′-(4″-chlorophenyl)-spiro[3H-indole-3,3′-[3H]-pyrrolizine] (3) have been synthesized and their 1H, 13C and 15N spectra assigned. The chemical shift assignments are based on Pulsed Field Gradient (PFG) Double Quantum Filter (DQF) 1H, 1H correlation spectroscopy (COSY), PFG 1H, 13C Heteronuclear Multiple Quantum Coherence (HMQC) and PFG 1H,X (X = 13C and 15N) Heteronuc…
Cytotoxic Spirostane-Type Saponins from the Roots of Chlorophytum borivilianum
2009
Four new spirostane-type saponins named borivilianosides E-H (1-4) were isolated from an ethanol extract of the roots of Chlorophytum borivilianum together with two known steroid saponins (5 and 6). The structures of 1-4 were elucidated using mainly 2D NMR spectroscopic techniques and mass spectrometry. The cytotoxicity of borivilianosides F (2), G (3), and H (4) and three known compounds was evaluated using two human colon cancer cell lines (HT-29 and HCT 116).