Broad spectrum pan-cadherin antibodies, reactive with the C-terminal 24 amino acid residues of N-cadherin

1990 ◽  
Vol 97 (4) ◽  
pp. 607-614
Author(s):  
B. Geiger ◽  
T. Volberg ◽  
D. Ginsberg ◽  
S. Bitzur ◽  
I. Sabanay ◽  
...  

We describe here the preparation and application of antibodies directed against a synthetic, 24 amino acid long, peptide corresponding to the conserved cytoplasmic C terminus of N-cadherin. We demonstrate here that the antibodies to the synthetic peptide react extensively with all known members of the cadherin family and, in addition, recognize novel cadherins in a variety of cells and tissues, suggesting that these antibodies indeed exhibit pan-cadherin reactivity. By Western blot screening of chicken tissues at least 4 different immunoreactive bands were resolved, commonly disclosing 2–3 distinct bands within the same tissue. The pan-cadherin antibodies also displayed a broad interspecies cross reactivity, recognizing cadherins in man, bovine, canine, avian, amphibian and teleost cells. This property renders these antibodies excellent reagents for the cloning and identification of novel cadherins. Immunocytochemical labelling with the pan-cadherin antibodies, at the light- and electron-microscope levels, revealed an extensive reactivity with intercellular adherens junctions in cardiac muscle and in various epithelia. We thus propose that the pan-cadherin antibodies may be used as ubiquitous cadherin probes and serve as markers for adherens junctions.

1992 ◽  
Vol 135 (3) ◽  
pp. 479-484 ◽  
Author(s):  
M. Ohmori ◽  
T. Endo ◽  
M. Ikeda ◽  
T. Onaya

ABSTRACT Eight rabbits were immunized with a synthetic peptide corresponding to the unique N-terminal region (termed N peptide; amino acid residues 29–57) in the extracellular domain of the human thyrotrophin (TSH) receptor. After 10 weeks, all of the eight rabbits produced anti-N peptide antibodies. Western blot analysis revealed that the antibodies recognized rabbit TSH receptor as an approximately 100 kDa protein. We compared the level of thyroid hormone in serum taken before immunization (preimmune sera) with that of serum taken after immunization (postimmune sera) in these immunized rabbits. Postimmune sera from the eight rabbits had higher mean (± s.d.) levels of tri-iodothyronine (T3) and thyroxine (T4) than did preimmune sera (T3, preimmune 0·82 ± 0·26 μg/l vs postimmune 1·33 ± 0·35, P < 0·01; T4, preimmune 33·7 ± 10·0 μg/l vs postimmune 41·0 ± 6·0, P < 0·05). T3 levels in four rabbits and T4 levels in four rabbits after immunization were over the normal range obtained from six age-matched control rabbits. Seven rabbits exhibited thyroid-stimulating antibody (TSAb) activity with various degrees (241–545%). The concentration of T3 and T4 did not increase over 10 weeks in either non-immunized rabbits (T3, preimmune 0·89 ± 0·34 μg/l vs postimmune 0·82 ± 0·22; T4, preimmune 31·1 ± 7·3 μg/l vs postimmune 30·3 ± 5·1) or other peptide-immunized rabbits (T3, preimmune 0·68 μg/l (n = 2) vs postimmune 0·69; T4, preimmune 33·1 μg/l vs postimmune 26·4). These results indicate that experimentally produced anti-TSH receptor antibody with TSAb activity induces an increase in thyroid hormone in rabbits. Journal of Endocrinology (1992) 135, 479–484


1988 ◽  
Vol 251 (3) ◽  
pp. 691-699 ◽  
Author(s):  
R W Olafson ◽  
W D McCubbin ◽  
C M Kay

Biochemical and physiological studies of Synechococcus cyanobacteria have indicated the presence of a low-Mr heavy-metal-binding protein with marked similarity to eukaryotic metallothioneins (MTs). We report here the characterization of a Synechococcus prokaryotic MT isolated by gel-permeation and reverse-phase chromatography. The large number of variants of this molecule found during chromatographic separation could not be attributed to the presence of major isoproteins as assessed by amino acid analysis and amino acid sequencing of isoforms. Two of the latter were shown to have identical primary structures that differed substantially from the well-described eukaryotic MTs. In addition to six long-chain aliphatic residues, two aromatic residues were found adjacent to one another near the centre of the molecule, making this the most hydrophobic MT to be described. Other unusual features included a pair of histidine residues located in repeating Gly-His-Thr-Gly sequences near the C-terminus and a complete lack of association of hydroxylated residues with cysteine residues, as is commonly found in eukaryotes. Similarly, aside from a single lysine residue, no basic amino acid residues were found adjacent to cysteine residues in the sequence. Most importantly, sequence alignment analyses with mammalian, invertebrate and fungal MT sequences showed no statistically significant homology aside from the presence of Cys-Xaa-Cys structures common to all MTs. On the other hand, like other MTs, the prokaryotic molecule appears to be free of alpha-helical structure but has a considerable amount of beta-structure, as predicted by both c.d. measurements and the Chou & Fasman empirical relations. Considered together, these data suggested that some similarity between the metal-thiolate clusters of the prokaryote and eukaryote MTs may exist.


1989 ◽  
Vol 3 (2) ◽  
pp. 105-112 ◽  
Author(s):  
T. S. Grewal ◽  
P. J. Lowry ◽  
D. Savva

ABSTRACT A large portion of the human pro-opiomelanocortin (POMC) peptide corresponding to amino acid residues 59–241 has been cloned and expressed in Escherichia coli. A 1·0 kb DNA fragment encoding this peptide was cloned into the expression vectors pUC8 and pUR291. Plasmid pJMBG51 (a pUC8 recombinant) was found to direct the expression of a 24 kDa peptide. The recombinant pUR291 (pJMBG52) was shown to produce a β-galactosidase fusion protein of 140 kDa. Western blot analysis showed that both the 24 kDa and 140 kDa peptides are recognized by antibodies raised against POMC-derived peptides. The β-galactosidase fusion protein has been partially purified from crude E. coli cell lysates using affinity chromatography on p-aminobenzyl-1-thio-β-d-galactopyranoside agarose.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 715
Author(s):  
Tamara Tomanić ◽  
Claire Martin ◽  
Holly Stefen ◽  
Esmeralda Parić ◽  
Peter Gunning ◽  
...  

Tropomyosins (Tpms) have been described as master regulators of actin, with Tpm3 products shown to be involved in early developmental processes, and the Tpm3 isoform Tpm3.1 controlling changes in the size of neuronal growth cones and neurite growth. Here, we used primary mouse hippocampal neurons of C57/Bl6 wild type and Bl6Tpm3flox transgenic mice to carry out morphometric analyses in response to the absence of Tpm3 products, as well as to investigate the effect of C-terminal truncation on the ability of Tpm3.1 to modulate neuronal morphogenesis. We found that the knock-out of Tpm3 leads to decreased neurite length and complexity, and that the deletion of two amino acid residues at the C-terminus of Tpm3.1 leads to more detrimental changes in neurite morphology than the deletion of six amino acid residues. We also found that Tpm3.1 that lacks the 6 C-terminal amino acid residues does not associate with stress fibres, does not segregate to the tips of neurites, and does not impact the amount of the filamentous actin pool at the axonal growth cones, as opposed to Tpm3.1, which lacks the two C-terminal amino acid residues. Our study provides further insight into the role of both Tpm3 products and the C-terminus of Tpm3.1, and it forms the basis for future studies that aim to identify the molecular mechanisms underlying Tpm3.1 targeting to different subcellular compartments.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Patamalai Boonserm ◽  
Songchan Puthong ◽  
Thanaporn Wichai ◽  
Sajee Noitang ◽  
Pongsak Khunrae ◽  
...  

AbstractIt is important to understand the amino acid residues that govern the properties of the binding between antibodies and ligands. We studied the binding of two anti-norfloxacins, anti-nor 132 and anti-nor 155, and the fluoroquinolones norfloxacin, enrofloxacin, ciprofloxacin, and ofloxacin. Binding cross-reactivities tested by an indirect competitive enzyme-linked immunosorbent assay indicated that anti-nor 132 (22–100%) had a broader range of cross-reactivity than anti-nor 155 (62–100%). These cross-reactivities correlated with variations in the numbers of interacting amino acid residues and their positions. Molecular docking was employed to investigate the molecular interactions between the fluoroquinolones and the monoclonal antibodies. Homology models of the heavy chain and light chain variable regions of each mAb 3D structure were docked with the fluoroquinolones targeting the crucial part of the complementarity-determining regions. The fluoroquinolone binding site of anti-nor 155 was a region of the HCDR3 and LCDR3 loops in which hydrogen bonds were formed with TYR (H:35), ASN (H:101), LYS (H:106), ASN (L:92), and ASN (L:93). These regions were further away in anti-nor 132 and could not contact the fluoroquinolones. Another binding region consisting of HIS (L:38) and ASP (H:100) was found for norfloxacin, enrofloxacin, and ciprofloxacin, whereas only ASP (H:100) was found for ofloxacin.


1989 ◽  
Vol 9 (1) ◽  
pp. 83-91
Author(s):  
S Miyazawa ◽  
T Osumi ◽  
T Hashimoto ◽  
K Ohno ◽  
S Miura ◽  
...  

To identify the topogenic signal of peroxisomal acyl-coenzyme A oxidase (AOX) of rat liver, we carried out in vitro import experiments with mutant polypeptides of the enzyme. Full-length AOX and polypeptides that were truncated at the N-terminal region were efficiently imported into peroxisomes, as determined by resistance to externally added proteinase K. Polypeptides carrying internal deletions in the C-terminal region exhibited much lower import activities. Polypeptides that were truncated or mutated at the extreme C terminus were totally import negative. When the five amino acid residues at the extreme C terminus were attached to some of the import-negative polypeptides, the import activities were rescued. Moreover, the C-terminal 199 and 70 amino acid residues of AOX directed fusion proteins with two bacterial enzymes to peroxisomes. These results are interpreted to mean that the peroxisome targeting signal of AOX residues at the C terminus and the five or fewer residues at the extreme terminus have an obligatory function in targeting. The C-terminal internal region also has an important role for efficient import, possibly through a conformational effect.


1996 ◽  
Vol 271 (1) ◽  
pp. C54-C60 ◽  
Author(s):  
M. Kimura ◽  
T. T. Andersen ◽  
J. W. Fenton ◽  
W. F. Bahou ◽  
A. Aviv

We tested the hypothesis that the inhibition of thrombin-induced platelet activation by plasmin is mediated via the enzymatic action of plasmin on the functional thrombin receptor. We monitored the binding of the anti-thrombin receptor antibody [anti-TR-(34-46)] to platelets; this binding is sensitive to the cleavage of the thrombin receptor at amino acid residues Arg-41 to Ser-42. Plasmin inhibited anti-TR-(34-46) binding in dose- and time-dependent manners. The inactive synthetic peptide with the amino acid sequence 40-55 of the thrombin receptor (D-FPRSFLLRNPNDKYEPF) was similarly cleaved by thrombin and plasmin to an active peptide (SFLLRNPNDKYEPF) that produced robust cytosolic Ca2+ responses. At high concentrations, plasmin itself can activate platelets. We explored this effect with the use of anti-TR-(1-160). This antibody abolished the cytosolic Ca2+ responses to thrombin and to the thrombin receptor-activating peptide SFLLRN but did not attenuate the plasmin-induced cytosolic Ca2+ response. Thus plasmin inhibits thrombin-evoked platelet activation by cleaving the thrombin receptor, but the plasmin-induced cytosolic Ca2+ response is not due to the generation of the tethered peptide of the thrombin receptor.


1999 ◽  
Vol 276 (2) ◽  
pp. R627-R631 ◽  
Author(s):  
Carles Garriga ◽  
Nativitat Rovira ◽  
Miquel Moretó ◽  
Joana M. Planas

We have studied the expression of Na+-d-glucose cotransporter in brush-border membrane vesicles (BBMVs) of chicken enterocytes to correlate the changes in the apical Na+-dependent transport with the changes in the amounts of transporter determined by Western blot analysis. Two different rabbit polyclonal antibodies were used simultaneously. The antibody raised against amino acids 564–575 of the deduced amino acid sequence of rabbit intestinal SGLT-1 ( antibody 1) specifically detects a single 75-kDa band in the three segments, and this band disappeared when the antibody was preabsorbed with the antigenic peptide. The antibody raised against the synthetic peptide corresponding to amino acids 402–420 of the same protein ( antibody 2) only reacts with jejunal and ileal samples, but no signal is found in BBMVs of rectum. Only when antibody 1 was used was there a linear correlation between the maximal transport rates of hexoses in BBMVs and the relative protein amounts determined by Western blot. These results indicate that the Na+-d-glucose cotransport in the jejunum, the ileum, and the rectum of chickens is due to an SGLT-1 type protein.


2006 ◽  
Vol 87 (4) ◽  
pp. 909-919 ◽  
Author(s):  
Grant S. Hansman ◽  
Katsuro Natori ◽  
Haruko Shirato-Horikoshi ◽  
Satoko Ogawa ◽  
Tomoichiro Oka ◽  
...  

Human norovirus (NoV) strains cause a considerable number of outbreaks of gastroenteritis worldwide. Based on their capsid gene (VP1) sequence, human NoV strains can be grouped into two genogroups (GI and GII) and at least 14 GI and 17 GII genotypes (GI/1–14 and GII/1–17). Human NoV strains cannot be propagated in cell-culture systems, but expression of recombinant VP1 in insect cells results in the formation of virus-like particles (VLPs). In order to understand NoV antigenic relationships better, cross-reactivity among 26 different NoV VLPs was analysed. Phylogenetic analyses grouped these NoV strains into six GI and 12 GII genotypes. An antibody ELISA using polyclonal antisera raised against these VLPs was used to determine cross-reactivity. Antisera reacted strongly with homologous VLPs; however, a number of novel cross-reactivities among different genotypes was observed. For example, GI/11 antiserum showed a broad-range cross-reactivity, detecting two GI and 10 GII genotypes. Likewise, GII/1, GII/10 and GII/12 antisera showed a broad-range cross-reactivity, detecting several other distinct GII genotypes. Alignment of VP1 amino acid sequences suggested that these broad-range cross-reactivities were due to conserved amino acid residues located within the shell and/or P1-1 domains. However, unusual cross-reactivities among different GII/3 antisera were found, with the results indicating that both conserved amino acid residues and VP1 secondary structures influence antigenicity.


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