An integrated top-down and bottom-up proteomic approach to characterize the antigen-binding fragment of antibodies.
We have previously shown that different individuals exposed to the same antigen produce antibodies with identical mutations in their complementarity determining regions (CDR), suggesting that CDR tryptic peptides can serve as biomarkers for disease diagnosis and prognosis.
Complete Fabs derived from disease-specific antibodies have even higher potential; they could potentially be used for disease treatment and are required to identify the antigens toward which the antibodies are directed. However, complete Fab sequence characterization via LC-MS analysis of tryptic peptides (i.e. bottom-up) has proven to be impractical for mixtures of antibodies.
To tackle this challenge, we have developed an integrated bottom-up and top-down MS approach, employing 2D chromatography coupled with Fourier transform mass spectrometry (FTMS), and applied this approach for full characterization of the variable parts of two pharmaceutical monoclonal antibodies with sensitivity comparable to the bottom-up standard.
These efforts represent an essential step toward the identification of disease specific antibodies in patient samples with potentially significant clinical impact.
Selective 351 nm photodissociation of cysteine-containing peptides for discrimination of antigen-binding regions of IgG fragments in bottom-up liquid chromatography-tandem mass spectrometry workflows.
Despite tremendous inroads in the development of more sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) strategies for mass spectrometry-based proteomics, there remains a significant need for enhancing the selectivity of MS/MS-based workflows for streamlined analysis of complex biological mixtures.
Here, a novel LC-MS/MS platform based on 351 nm ultraviolet photodissociation (UVPD) is presented for the selective analysis of cysteine-peptide subsets in complex protein digests. Cysteine-selective UVPD is mediated through the site-specific conjugation of reduced cysteine residues with a 351 nm active chromogenic Alexa Fluor 350 (AF350) maleimide tag.
Only peptides containing the AF350 chromophore undergo photodissociation into extensive arrays of b- and y-type fragment ions, thus providing a facile means for differentiating cysteine-peptide targets from convoluting peptide backgrounds.
With the use of this approach in addition to strategic proteolysis, the selective analysis of diagnostic heavy-chain complementarity determining regions (CDRs) of single-chain antibody (scAb) fragments is demonstrated.
Fragments of the Roelofs effect: a bottom-up effect equal to the sum of its parts.
The Roelofs effect is a distortion of perceived space that occurs when a large frame whose center is offset left or right from the objective midline is presented visually to an observer and causes a bias in the observer’s subjective judgment of midline.
Experiments were designed to test whether an isolated fragment (left or right end) of a Roelofs-inducing frame was capable of generating the Roelofs effect and to determine whether prior experience with intact frames would provide a top-down influence that would bias the Roelofs effect resulting from fragment presentation.
Although the fragments did induce an effect, top-down information did not play a significant role even after a 5-day training paradigm. Instead, we found that the effect generated by an intact frame was equal in magnitude to the sum of the effects generated by the individual fragments.
In addition, perception was found to be differentially affected by the two ends of the frame, with fragments falling in the right visual field causing a larger effect than those falling in the left.
Description: A competitive ELISA for quantitative measurement of Porcine Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Dog Rhizopus arrhizu Fatty Acid Desaturases 6 ELISA kit
Description: A competitive ELISA for quantitative measurement of Canine Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Dog Rhizopus arrhizu Fatty Acid Desaturases 6 ELISA kit
Description: A competitive ELISA for quantitative measurement of Canine Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Dog Rhizopus arrhizu Fatty Acid Desaturases 6 ELISA kit
Description: A competitive ELISA for quantitative measurement of Canine Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Rat Rhizopus arrhizu Fatty Acid Desaturases 6 ELISA kit
Description: A competitive ELISA for quantitative measurement of Goat Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Goat Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Goat Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Mouse Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Mouse Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Mouse Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Human Rhizopus arrhizu Fatty Acid Desaturases 6 ELISA kit
Description: A competitive ELISA for quantitative measurement of Human Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Human Rhizopus arrhizu Fatty Acid Desaturases 6 ELISA kit
Description: A competitive ELISA for quantitative measurement of Human Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Human Rhizopus arrhizu Fatty Acid Desaturases 6 ELISA kit
Description: A competitive ELISA for quantitative measurement of Human Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Human Rhizopus arrhizu Fatty Acid Desaturases 6 ELISA kit
Description: A competitive ELISA for quantitative measurement of Rabbit Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Rabbit Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Rabbit Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Monkey Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Monkey Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Monkey Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Guinea pig Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Guinea pig Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: A competitive ELISA for quantitative measurement of Guinea pig Rhizopus arrhizu Fatty Acid Desaturases 6 in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.
Description: Aspergillus Oryzae (strain ATCC 42149 / RIB 40) (Yellow koji mold) Spindle Pole Body Protein, recombinant protein.
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Induction of cell cycle arrest and apoptosis by tomentosin in hepatocellular carcinoma HepG2 and Huh7 cells.
Tomentosin, a sesquiterpene lactone, is known to possess various biological activities. However, its anticarcinogenic activity against human hepatocellular carcinoma (HCC) cells has not been investigated in detail. Thus, this study aimed to elucidate the cytotoxic mechanism of tomentosin in human HCC cell lines HepG2 and Huh7.
WST-1, cell counting, and colony formation assay results showed that treatment with tomentosin decreased the viability and suppressed the proliferation rate of HepG2 and Huh7 cells in a dose- and time-dependent manner. Cell cycle analysis revealed increased population of cells at the SubG1 and G2/M stage, and decreased population of cells at the G0/1 stage in HepG2 and Huh7 cells treated with tomentosin.
Annexin V/propidium iodide double staining and TUNEL assay results showed increased apoptotic cell population and DNA fragmentation in HepG2 and Huh7 cells treated with tomentosin.
Western blotting analysis results showed that tomentosin treatment significantly increased the expression level of Bax, Bim (short form), cleaved PARP1, FOXO3, p53, pSer15p53, pSer20p53, pSer46p53, p21, and p27, but decreased the expression of Bcl2, caspase3, caspase7, caspase9, cyclin-dependent kinase 2 (CDK2), CDK4, CDK6, cyclinB1, cyclinD1, cyclinD2, cyclinD3, and cyclinE in a dose-dependent manner.
Taken together, this study revealed that tomentosin, which acted through cell cycle arrest and apoptosis, may be a useful therapeutic option against HCC.