Loricrin C-terminal Antibody [D17A11]

N° de catalogue F3698

Imprimer

Description biologique

Spécificité Loricrin C-terminal Antibody [D17A11] détecte les niveaux endogènes de la région C-terminale de la protéine Loricrin totale.
Contexte Le domaine C-terminal de la loricrine constitue la région d'ancrage riche en glutamine et en lysine de cette protéine prédominante de l'enveloppe cornée (CE) (représentant plus de 70 % de la masse épidermique), caractérisée par des boucles glycine-sérine avec de multiples paires Q/K – telles que les clusters Gln451/Lys454 – qui agissent comme des substrats primaires de la transglutaminase 1/3 (TGM1/3) pour la formation de liaisons isopeptidiques ε-(γ-glutamyl)lysine, renforcées en outre par des ponts disulfure de cystéine conférant l'insolubilité. Pendant la différenciation terminale des kératinocytes, la TGM1 activée par Ca²⁺ assure une réticulation séquentielle intra- et extracellulaire, où les résidus glutamine C-terminaux sont désamidés en glutamates pour amorcer les groupes ε-amino de lysine pour une attaque nucléophile, ancrant rigidement la loricrine à l'échafaudage d'involucrine/petite protéine riche en proline (SPR) dans les granules L et ensuite à la membrane plasmique, résultant en une coque de 10 à 20 nm d'épaisseur, mécaniquement résiliente, imperméable à l'eau et aux pathogènes, avec des boucles de glycine flexibles absorbant les contraintes de traction (module ~100 MPa). Cette insolubilisation post-traductionnelle via la polymérisation en réseau catalysée par TGM établit mécaniquement la compétence de la barrière épidermique, régulée transcriptionnellement par la surexpression de LOR médiée par NFAT, AP1 et NRF2. Des mutations dominantes par décalage du cadre de lecture tronquant l'extrémité C-terminale produisent des peptides de signal de localisation nucléaire (NLS) riches en arginine qui se localisent de manière ectopique dans le noyau et altèrent la réticulation, perturbant de manière dominante la différenciation terminale et entraînant la kératodermie de loricrine (LK/syndrome de Vohwinkel), caractérisée par une hyperkératose palmoplantaire, une ichthyose et une fragilité de la barrière due à des enveloppes cornées incompétentes.

Informations dutilisation

Application IHC, IF Dilution
IHC IF
1:250 1:250
Réactivité Rat, Human
Source Rabbit Monoclonal Antibody MW
Tampon de stockage PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3
Stockage
(À partir de la date de réception)
-20°C (avoid freeze-thaw cycles), 2 years
IHC
Experimental Protocol:
 
Deparaffinization/Rehydration
1. Deparaffinize/hydrate sections:
2. Incubate sections in three washes of xylene for 5 min each.
3. Incubate sections in two washes of 100% ethanol for 10 min each.
4. Incubate sections in two washes of 95% ethanol for 10 min each.
5. Wash sections two times in dH2O for 5 min each.
6.Antigen retrieval: For Citrate: Heat slides in a microwave submersed in 1X citrate unmasking solution until boiling is initiated; continue with 10 min at a sub-boiling temperature (95°-98°C). Cool slides on bench top for 30 min.
 
Staining
1. Wash sections in dH2O three times for 5 min each.
2. Incubate sections in 3% hydrogen peroxide for 10 min.
3. Wash sections in dH2O two times for 5 min each.
4. Wash sections in wash buffer for 5 min.
5. Block each section with 100–400 µl of blocking solution for 1 hr at room temperature.
6. Remove blocking solution and add 100–400 µl primary antibody diluent in to each section. Incubate overnight at 4°C.
7. Remove antibody solution and wash sections with wash buffer three times for 5 min each.
8. Cover section with 1–3 drops HRPas needed. Incubate in a humidified chamber for 30 min at room temperature.
9. Wash sections three times with wash buffer for 5 min each.
10. Add DAB Chromogen Concentrate to DAB Diluent and mix well before use.
11. Apply 100–400 µl DAB to each section and monitor closely. 1–10 min generally provides an acceptable staining intensity.
12. Immerse slides in dH2O.
13. If desired, counterstain sections with hematoxylin.
14. Wash sections in dH2O two times for 5 min each.
15. Dehydrate sections: Incubate sections in 95% ethanol two times for 10 sec each; Repeat in 100% ethanol, incubating sections two times for 10 sec each; Repeat in xylene, incubating sections two times for 10 sec each.
16. Mount sections with coverslips and mounting medium.
 
IF
Experimental Protocol:
 
Sample Preparation
1. Adherent Cells: Place a clean, sterile coverslip in a culture dish. Once the cells grow to near confluence as a monolayer, remove the coverslip for further use.
2. Suspension Cells: Seed the cells onto a clean, sterile slide coated with poly-L-lysine.
3. Frozen Sections: Allow the slide to thaw at room temperature. Wash it with pure water or PBS for 2 times, 3 minutes each time.
4. Paraffin Sections: Deparaffinization and rehydration. Wash the slide with pure water or PBS for 3 times, 3 minutes each time. Then perform antigen retrieval.
 
Fixation
1. Fix the cell coverslips/spots or tissue sections at room temperature using a fixative such as 4% paraformaldehyde (4% PFA) for 10-15 minutes.
2. Wash the sample with PBS for 3 times, 3 minutes each time.
 
Permeabilization
1.Add a detergent such as 0.1–0.3% Triton X-100 to the sample and incubate at room temperature for 10–20 minutes.
(Note: This step is only required for intracellular antigens. For antigens expressed on the cell membrane, this step is unnecessary.)
Wash the sample with PBS for 3 times, 3 minutes each time.
 
Blocking
Add blocking solution and incubate at room temperature for at least 1 hour. (Common blocking solutions include: serum from the same source as the secondary antibody, BSA, or goat serum.)
Note: Ensure the sample remains moist during and after the blocking step to prevent drying, which can lead to high background.
 
Immunofluorescence Staining (Day 1)
1. Remove the blocking solution and add the diluted primary antibody.
2. Incubate the sample in a humidified chamber at 4°C overnight.
 
Immunofluorescence Staining (Day 2)
1. Remove the primary antibody and wash with PBST for 3 times, 5 minutes each time.
2. Add the diluted fluorescent secondary antibody and incubate in the dark at 4°C for 1–2 hours.
3. Remove the secondary antibody and wash with PBST for 3 times, 5 minutes each time.
4. Add diluted DAPI and incubate at room temperature in the dark for 5–10 minutes.
5. Wash with PBST for 3 times, 5 minutes each time.
 
Mounting
1. Mount the sample with an anti-fade mounting medium.
2. Allow the slide to dry at room temperature overnight in the dark.
3. Store the slide in a slide storage box at 4°C, protected from light.
 

Références

  • https://pubmed.ncbi.nlm.nih.gov/35625601/
  • https://pubmed.ncbi.nlm.nih.gov/8673107/

Données dapplication