scholarly journals Biochemical characterization of a rat oncofetal colonic antigen defined by a monoclonal antibody raised against gastric surface epithelium

1993 ◽  
Vol 293 (2) ◽  
pp. 531-536 ◽  
Author(s):  
C Decaens ◽  
J Nardelli ◽  
J Bara ◽  
P Burtin
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibody ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Disulphide Bond ◽  
Trypsin Digestion ◽  
Surface Epithelium ◽  
Mucin Glycoproteins ◽  
Peptide Core ◽  
Mucus Glycoproteins

The 660 epitope was defined by a monoclonal antibody raised against rat gastric surface epithelium scrapings. This epitope, a marker of goblet cell differentiation, shows oncofetal behaviour in the colonic mucosa. We found that it co-purified with gastric mucin glycoproteins. We isolated rat gastric mucus glycoproteins using standard techniques: gastric scrapings in PBS were submitted to isopycnic density gradient centrifugation in CsCl in the presence of proteinase inhibitors. Fractions of relative density 1.4-1.45 with a high neutral sugar/protein ratio were chromatographed on an Ultrogel A4 column. According to the usual criteria, the high-molecular mass glycoproteins recovered in the excluded volume were purified mucins; when stained with periodic acid/Schiff reagent, they showed little migration on 4-15% gradient gel acrylamide electrophoresis. Serine+threonine+proline residues accounted for 35% of the total amino acids; the carbohydrate composition consisted of galactose, fucose, N-acetylgalactosamine and N-acetylglucosamine. These mucus glycoproteins carried the 660 epitope. After disulphide bond reduction, the remaining high-molecular-mass subunits were retained by the Ultrogel A4 column; amino acid and saccharide compositions were generally similar to those of the unreduced fraction. Trypsin digestion of the 660 epitope glycoprotein carrier did not modify its chromatographic and electrophoretic patterns, nor its chemical composition. The 660 epitope was still present after these treatments. However, trypsin digestion of subunits gave rise to smaller components that were retained by an Ultrogel A4 column. The saccharide composition of these fragments was unchanged, but the proportion of serine+threonine+proline residues rose to 46% of the total. These digested subunits had lost nearly all reactivity with monoclonal antibody 660. Our results fit well with the macromolecular model of Carlstedt, Lindgren and Sheehan [(1983) Biochem. J. 213, 427-435]: mucin glycoproteins are homopolymers of subunits assembled end-to-end via disulphide bonds into very large linear macromolecules. After disulphide bond reduction, proteolytic attack sites are uncovered and trypsin digestion results in glycopeptides bearing the typical oligosaccharidic units and with enhanced amounts of serine, threonine and proline, the characteristic amino acids of this hyperglycosylated region of the peptide core. These digested subunits have lost virtually all 660 epitope reactivity. We thus show that the 660 epitope, a determinant of a mucin molecule, is probably associated with the peptide core of the glycoprotein.

scholarly journals Monoclonal antibody studies of creatine kinase. The ART epitope: evidence for an intermediate in protein folding

1989 ◽  
Vol 257 (2) ◽  
pp. 461-469 ◽  
Author(s):  
G E Morris
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibody ◽  
Creatine Kinase ◽  
Specific Binding ◽  
Trypsin Digestion ◽  
Proteinase K ◽  
Enzyme Linked Immunosorbent Assay ◽  
Muscle Creatine Kinase ◽  
Western Blots ◽  
Methionine Residues

Chemical cleavage at cysteine residues with nitrothiocyanobenzoic acid shows that the last 98 amino acids of the 380-amino-acid sequence of chick muscle creatine kinase are sufficient for binding of the monoclonal antibody CK-ART. Removal of the last 30 amino acids by cleavage at methionine residues with CNBr results in loss of CK-ART binding. CK-ART binding is also lost when these C-terminal methionine residues are oxidized to sulphoxide, but binding is regained on reduction. Proteinase K ‘nicks’ native CK at a single site near the C-terminus and two fragments of 327 amino acides and 53 amino acids can be separated by subsequent SDS or urea treatment. CK-ART still binds normally to ‘nicked’ CK, which is enzymically inactive. After treatment with either urea (in a competition enzyme-linked immunosorbent assay) or SDS (on Western blots), however, CK-ART binds to neither of the two fragments, although these treatments do not affect binding to intact CK. This suggests that parts of both CK fragments contribute to the CK-ART epitope. CK-ART is both species- and isoenzyme-specific, binding only to chick M-CK. The only C-terminal regions containing chick-specific sequences are residues 300-312 and residues 368-371, the latter group being close to the essential methionine residues. We suggest that one, or possibly both, of these regions is involved in forming the conformational epitope on the surface of the CK molecule which CK-ART recognizes. Native CK is resistant to trypsin digestion. The C-terminal half of urea-treated and partly-refolded CK is also resistant to trypsin digestion, whereas the N-terminal half is readily digested. The results suggest a C-terminal region which can refold more rapidly than the rest of the CK molecule and provide evidence for an intermediate in CK refolding.

Distribution of nonsugars in the ARi Coupled Loop molasses desugarization system

2011 ◽  
pp. 660-662
Author(s):  
D. Eugene Rearick ◽  
Cheri McKay ◽  
Alla Bagramyan
Keyword(s):  
Amino Acids ◽  
Organic Acids ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Inorganic Anions ◽  
Distribution Data ◽  
Total Solids ◽  
Composite Samples ◽  
Color Components

Weekly factory composite samples of feed and all exiting streams (after concentration) from a normally operating factory Coupled Loop molasses desugarization system were analyzed for sucrose, betaine, raffinose, common cations, inorganic anions, common organic acids, and amino acids. The percentage of total solids accounted for in all analyses was highest in the betaine fraction (which contains the highest proportion of betaine and amino acids) and lowest in feed and raffinate streams, which contain color components, high molecular mass compounds, and other unidentified materials. Distribution data for all analytes as aforementioned are given.

scholarly journals A new high molecular mass protein showing unique localization in desmosomal plaque.

1989 ◽  
Vol 109 (4) ◽  
pp. 1511-1518 ◽  
Author(s):  
Y Hieda ◽  
S Tsukita ◽  
S Tsukita
Keyword(s):  
Monoclonal Antibody ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Binding Ability ◽  
Stratified Epithelium ◽  
Keratin Filaments

A high molecular mass protein of 680 kD was identified and purified from the isolated desmosomes in bovine muzzle epidermal cells. This protein, called "desmoyokin" (from the English, yoke) here, showed no binding ability with keratin filaments in vitro, and its molecule had a characteristic dumbell shape approximately 170 nm in length. We have succeeded in obtaining one monoclonal antibody specific to desmoyokin. By the use of this monoclonal antibody and antidesmoplakin monoclonal antibody, desmoyokin was shown to be colocalized with desmoplakin at the immunofluorescence microscopic level; desmoyokin occurred only in the stratified epithelium, not in the simple epithelium nor in the other tissues. At the electron microscopic level, these two proteins were clearly seen to be sorted out in the plaque of desmosomes with desmoyokin at the periphery and desmoplakin at the center of the disk-shaped desmosomal plaque, suggesting that these two plaque proteins play distinct roles in forming and maintaining the desmosomes in stratified epithelium.

scholarly journals Microinjection of a monoclonal antibody against SPN antigen, now identified by peptide sequences as the NuMA protein, induces micronuclei in PtK2 cells

1993 ◽  
Vol 104 (1) ◽  
pp. 139-150 ◽  
Author(s):  
M. Kallajoki ◽  
J. Harborth ◽  
K. Weber ◽  
M. Osborn
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibody ◽  
Functional Role ◽  
Cyanogen Bromide ◽  
Interphase Nucleus ◽  
Cdna Sequence ◽  
High Molecular Mass ◽  
Daughter Cells ◽  
Spindle Poles ◽  
Cells With Micronuclei

Several high molecular mass proteins which relocate from the interphase nucleus to the spindle poles during mitosis have been defined by antibodies. Microinjection experiments have shown that at least the antigen defined by SPN antibody plays a functional role during mitosis. Recently the cDNA sequence for human NuMA antigen was established and epitopes for antibodies to centrophilin, and to 1F1 and 1H1 antigens were found to be included in the NuMA protein. Here we show that immunoprecipitated SPN antigen reacts with an autoimmune human NuMA serum. In addition three peptides derived from immunoprecipitated human SPN by cyanogen bromide cleavage and covering more than fifty amino acids show a perfect fit with the sequence predicted for NuMA protein. Thus SPN antigen and NuMA are the same protein. Injection of SPN-3 antibody into interphase or mitotic PtK2 cells results in cells with micronuclei. For cells injected in prophase, prometaphase or metaphase 90%, 78% and 77% display defective cytokinesis or yield daughter cells with micronuclei. In contrast only 16% of cells injected in anaphase are abnormal. Thus SPN/NuMA antigen may be required during early, but not during later, stages of mitosis. Surprising parallels are seen between the effects of microinjecting SPN-3 antibody and treatment with colcemid and taxol of PtK2 and HeLa cells. Our results identify an important role during mitosis for the SPN/NuMA antigen.

High molecular mass kininogen inhibits cathepsin G-induced platelet activation by forming a complex with cathepsin G

2001 ◽  
Vol 2 (6) ◽  
pp. 371-377 ◽  
Author(s):  
Tarek E Selim ◽  
Hayam R Ghoneim ◽  
Hassan A Abdel Ghaffar ◽  
Robert W Colman ◽  
Raul A Dela Cadena
Keyword(s):  
Molecular Mass ◽  
Platelet Activation ◽  
High Molecular Mass ◽  
Cathepsin G

scholarly journals Analysis of High Molecular Mass Compounds from the Spider Pamphobeteus verdolaga Venom Gland. A Transcriptomic and MS ID Approach

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 453
Author(s):  
Sebastian Estrada-Gómez ◽  
Leidy Johana Vargas-Muñoz ◽  
Cesar Segura Latorre ◽  
Monica Maria Saldarriaga-Cordoba ◽  
Claudia Marcela Arenas-Gómez
Keyword(s):  
Enzymatic Activity ◽  
Molecular Mass ◽  
Evolutionary Relationship ◽  
Venom Gland ◽  
Duplication Event ◽  
High Molecular Mass ◽  
Amino Acid Sequences ◽  
Secretory Proteins ◽  
Phospholipases A2 ◽  
Kunitz Type

Nowadays, spider venom research focuses on the neurotoxic activity of small peptides. In this study, we investigated high-molecular-mass compounds that have either enzymatic activity or housekeeping functions present in either the venom gland or venom of Pamphobeteus verdolaga. We used proteomic and transcriptomic-assisted approaches to recognize the proteins sequences related to high-molecular-mass compounds present in either venom gland or venom. We report the amino acid sequences (partial or complete) of 45 high-molecular-mass compounds detected by transcriptomics showing similarity to other proteins with either enzymatic activity (i.e., phospholipases A2, kunitz-type, hyaluronidases, and sphingomyelinase D) or housekeeping functions involved in the signaling process, glucanotransferase function, and beta-N-acetylglucosaminidase activity. MS/MS analysis showed fragments exhibiting a resemblance similarity with different sequences detected by transcriptomics corresponding to sphingomyelinase D, hyaluronidase, lycotoxins, cysteine-rich secretory proteins, and kunitz-type serine protease inhibitors, among others. Additionally, we report a probably new protein sequence corresponding to the lycotoxin family detected by transcriptomics. The phylogeny analysis suggested that P. verdolaga includes a basal protein that underwent a duplication event that gave origin to the lycotoxin proteins reported for Lycosa sp. This approach allows proposing an evolutionary relationship of high-molecular-mass proteins among P. verdolaga and other spider species.

scholarly journals Development of a New Highly Selective Monoclonal Antibody against Preferentially Expressed Antigen in Melanoma (PRAME) and Identification of the Target Epitope by Bio-Layer Interferometry

2021 ◽  
Vol 22 (6) ◽  
pp. 3166
Author(s):  
Jwala Priyadarsini Sivaccumar ◽  
Antonio Leonardi ◽  
Emanuela Iaccarino ◽  
Giusy Corvino ◽  
Luca Sanguigno ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Western Blotting ◽  
Cancer Biomarkers ◽  
Trypsin Digestion ◽  
Protein Fragments ◽  
Target Epitope ◽  
Potential Activity ◽  
Antibody Epitopes

Background: Monoclonal antibodies (mAbs) against cancer biomarkers are key reagents in diagnosis and therapy. One such relevant biomarker is a preferentially expressed antigen in melanoma (PRAME) that is selectively expressed in many tumors. Knowing mAb’s epitope is of utmost importance for understanding the potential activity and therapeutic prospective of the reagents. Methods: We generated a mAb against PRAME immunizing mice with PRAME fragment 161–415; the affinity of the antibody for the protein was evaluated by ELISA and SPR, and its ability to detect the protein in cells was probed by cytofluorimetry and Western blotting experiments. The antibody epitope was identified immobilizing the mAb on bio-layer interferometry (BLI) sensor chip, capturing protein fragments obtained following trypsin digestion and performing mass spectrometry analyses. Results: A mAb against PRAME with an affinity of 35 pM was obtained and characterized. Its epitope on PRAME was localized on residues 202–212, taking advantage of the low volumes and lack of fluidics underlying the BLI settings. Conclusions: The new anti-PRAME mAb recognizes the folded protein on the surface of cell membranes suggesting that the antibody’s epitope is well exposed. BLI sensor chips can be used to identify antibody epitopes.

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