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FKBP12 Mouse mAb

Catalog No.: F3489

Application: Reactivity: Human, Mouse, Rat

Experiment Essentials

WB
Recommended SDS-PAGE separating gel concentration: 20%.
Recommended wet transfer conditions: 200 mA, 60 min，Recommended to use 0.22 μm PVDF membrane.
Recommended WB dilution ratio: 1:100

Usage Information

Dilution
WB1:100-1:1000 IP1-2 µg per 100-500 µg of total protein (1 ml of cell lysate) IF1:50-1:500

Application
WB, IP, IF, ELISA

Reactivity
Human, Mouse, Rat

Source
Mouse

Storage Buffer
PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN₃

Storage (from the date of receipt)
-20°C (avoid freeze-thaw cycles), 2 years

Predicted MW Observed MW
12 kDa 12 kDa
^*Why do the predicted and actual molecular weights differ? The following reasons may explain differences between the predicted and actual protein molecular weight.

Exprimental Methods

WB
Experimental Protocol: Sample preparation 1. Tissue: Lyse the tissue sample by adding an appropriate volume of ice-cold RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail)，and homogenize the tissue at a low temperature. 2. Adherent cell: Aspirate the culture medium and wash the cells with ice-cold PBS twice. Lyse the cells by adding an appropriate volume of RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail) and put the sample on ice for 5 min. 3. Suspension cell: Transfer the culture medium to a pre-cooled centrifuge tube. Centrifuge and aspirate the supernatant. Wash the cells with ice-cold PBS twice. Lyse the cells by adding an appropriate volume of RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail) and put the sample on ice for 5 min. 4. Place the lysate into a pre-cooled microcentrifuge tube. Centrifuge at 4°C for 15 min. Collect the supernatant; 5. Remove a small volume of lysate to determine the protein concentration; 6. Combine the lysate with protein loading buffer. Boil 20 µL sample under 95-100°C for 5 min. Centrifuge for 5 min after cool down on ice. Electrophoretic separation 1. According to the concentration of extracted protein, load appropriate amount of protein sample and marker onto SDS-PAGE gels for electrophoresis. Recommended separating gel (lower gel) concentration: 20%. Reference Table for Selecting SDS-PAGE Separation Gel Concentrations 2. Power up 80V for 30 minutes. Then the power supply is adjusted (110 V~150 V), the Marker is observed, and the electrophoresis can be stopped when the indicator band of the predyed protein Marker where the protein is located is properly separated. (Note that the current should not be too large when electrophoresis, too large current (more than 150 mA) will cause the temperature to rise, affecting the result of running glue. If high currents cannot be avoided, an ice bath can be used to cool the bath.) Transfer membrane 1. Take out the converter, soak the clip and consumables in the pre-cooled converter; 2. Activate PVDF membrane with methanol for 1 min and rinse with transfer buffer; 3. Install it in the order of "black edge of clip - sponge - filter paper - filter paper - glue -PVDF membrane - filter paper - filter paper - sponge - white edge of clip"; 4. The protein was electrotransferred to PVDF membrane. ( 0.22 µm PVDF membrane is recommended )） Reference Table for Selecting PVDF Membrane Pore Size Specifications Recommended conditions for wet transfer: 200 mA, 60 min. ( Note that the transfer conditions can be adjusted according to the protein size. For high-molecular-weight proteins, a higher current and longer transfer time are recommended. However, ensure that the transfer tank remains at a low temperature to prevent gel melting.) Block 1. After electrotransfer, wash the film with TBST at room temperature for 5 minutes; 2. Incubate the film in the blocking solution for 1 hour at room temperature; 3. Wash the film with TBST for 3 times, 5 minutes each time. Antibody incubation 1. Use 5% skim milk powder to prepare the primary antibody working liquid (recommended dilution ratio for primary antibody 1:100), gently shake and incubate with the film at 4°C overnight; 2. Wash the film with TBST 3 times, 5 minutes each time; 3. Add the secondary antibody to the blocking solution and incubate with the film gently at room temperature for 1 hour; 4. After incubation, wash the film with TBST 3 times for 5 minutes each time. Antibody staining 1. Add the prepared ECL luminescent substrate (or select other color developing substrate according to the second antibody) and mix evenly; 2. Incubate with the film for 1 minute, remove excess substrate (keep the film moist), wrap with plastic film, and expose in the imaging system.

Experimental Protocol:

Sample preparation

1. Tissue: Lyse the tissue sample by adding an appropriate volume of ice-cold RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail)，and homogenize the tissue at a low temperature.

2. Adherent cell: Aspirate the culture medium and wash the cells with ice-cold PBS twice. Lyse the cells by adding an appropriate volume of RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail) and put the sample on ice for 5 min.

3. Suspension cell: Transfer the culture medium to a pre-cooled centrifuge tube. Centrifuge and aspirate the supernatant. Wash the cells with ice-cold PBS twice. Lyse the cells by adding an appropriate volume of RIPA/NP-40 Lysis Buffer (containing Protease Inhibitor Cocktail) and put the sample on ice for 5 min.

4. Place the lysate into a pre-cooled microcentrifuge tube. Centrifuge at 4°C for 15 min. Collect the supernatant;

5. Remove a small volume of lysate to determine the protein concentration;

6. Combine the lysate with protein loading buffer. Boil 20 µL sample under 95-100°C for 5 min. Centrifuge for 5 min after cool down on ice.

Electrophoretic separation

1. According to the concentration of extracted protein, load appropriate amount of protein sample and marker onto SDS-PAGE gels for electrophoresis. Recommended separating gel (lower gel) concentration: 20%. Reference Table for Selecting SDS-PAGE Separation Gel Concentrations

2. Power up 80V for 30 minutes. Then the power supply is adjusted (110 V~150 V), the Marker is observed, and the electrophoresis can be stopped when the indicator band of the predyed protein Marker where the protein is located is properly separated. (Note that the current should not be too large when electrophoresis, too large current (more than 150 mA) will cause the temperature to rise, affecting the result of running glue. If high currents cannot be avoided, an ice bath can be used to cool the bath.)

Transfer membrane

1. Take out the converter, soak the clip and consumables in the pre-cooled converter;

2. Activate PVDF membrane with methanol for 1 min and rinse with transfer buffer;

3. Install it in the order of "black edge of clip - sponge - filter paper - filter paper - glue -PVDF membrane - filter paper - filter paper - sponge - white edge of clip";

4. The protein was electrotransferred to PVDF membrane. ( 0.22 µm PVDF membrane is recommended )） Reference Table for Selecting PVDF Membrane Pore Size Specifications

Recommended conditions for wet transfer: 200 mA, 60 min.

( Note that the transfer conditions can be adjusted according to the protein size. For high-molecular-weight proteins, a higher current and longer transfer time are recommended. However, ensure that the transfer tank remains at a low temperature to prevent gel melting.)

Block

1. After electrotransfer, wash the film with TBST at room temperature for 5 minutes;

2. Incubate the film in the blocking solution for 1 hour at room temperature;

3. Wash the film with TBST for 3 times, 5 minutes each time.

Antibody incubation

1. Use 5% skim milk powder to prepare the primary antibody working liquid (recommended dilution ratio for primary antibody 1:100), gently shake and incubate with the film at 4°C overnight;

2. Wash the film with TBST 3 times, 5 minutes each time;

3. Add the secondary antibody to the blocking solution and incubate with the film gently at room temperature for 1 hour;

4. After incubation, wash the film with TBST 3 times for 5 minutes each time.

Antibody staining

1. Add the prepared ECL luminescent substrate (or select other color developing substrate according to the second antibody) and mix evenly;

2. Incubate with the film for 1 minute, remove excess substrate (keep the film moist), wrap with plastic film, and expose in the imaging system.

IF
Experimental Protocol： Specimen Preparation 1. Aspirate liquid, then cover cells to a depth of 2–3 mm with 4% Paraformaldehyde diluted in 1X PBS. NOTE: Paraformaldehyde is toxic, use only in a fume hood. 2. Fix cells for 15 min at room temperature. 3. Aspirate fixative, rinse three times in 1X PBS for 5 min each. 4. Proceed with Immunostaining. Immunostaining 1. Add theblocking buffer and incubate for 60 min at RT. 2. Prepare primary antibody diluent in antibody dilution buffer as recommended . 3. Aspirate blocking solution, apply diluted primary antibody. 4. Incubate overnight at 4°C. 5. Rinse three times in 1X PBS for 5 min each. 6. Incubate specimens in fluorochrome-conjugated secondary antibody diluted in antibody dilution buffer for 1–2 hr at room temperature in the dark. 7. Rinse three times in 1X PBS for 5 min each. 8. Mount slides usingmounting medium with DAPI and cover with coverslips. 9. For best results, allow mountant to cure overnight at room temperature. For long-term storage, store slides flat at 43°C protected from light.

Experimental Protocol：

Specimen Preparation

1. Aspirate liquid, then cover cells to a depth of 2–3 mm with 4% Paraformaldehyde diluted in 1X PBS.

NOTE: Paraformaldehyde is toxic, use only in a fume hood.

2. Fix cells for 15 min at room temperature.

3. Aspirate fixative, rinse three times in 1X PBS for 5 min each.

4. Proceed with Immunostaining.

Immunostaining

1. Add theblocking buffer and incubate for 60 min at RT.

2. Prepare primary antibody diluent in antibody dilution buffer as recommended .

3. Aspirate blocking solution, apply diluted primary antibody.

4. Incubate overnight at 4°C.

5. Rinse three times in 1X PBS for 5 min each.

6. Incubate specimens in fluorochrome-conjugated secondary antibody diluted in antibody dilution buffer for 1–2 hr at room temperature in the dark.

7. Rinse three times in 1X PBS for 5 min each.

8. Mount slides usingmounting medium with DAPI and cover with coverslips.

9. For best results, allow mountant to cure overnight at room temperature. For long-term storage, store slides flat at 43°C protected from light.

Datasheet & SDS

Biological Description

Specificity
FKBP12 Mouse mAb recognizes endogenous levels of total FKBP12 protein.

Subcellular Location
Cytoplasm, Membrane, Sarcoplasmicreticulum

Uniprot ID
P62942,P68106

Clone
H17G5

Synonym(s)
Peptidyl-prolyl cis-trans isomerase FKBP1A, PPIase FKBP1A, Calstabin-1, FK506-binding protein 1A (FKBP-1A), Immunophilin FKBP12, Rotamase, FKBP1

Background
FKBP12 is a cytosolic protein belonging to the immunophilin family, ubiquitously expressed in all tissues and functions primarily as a peptidyl-prolyl cis/trans isomerase (PPIase), facilitating protein folding and acting as a molecular chaperone. Structurally, FKBP12 contains a single PPIase domain with a compact globular fold and a hydrophobic pocket that binds natural substrates and immunosuppressive drugs such as FK506 and rapamycin. Although drug binding inhibits its PPIase activity, the immunosuppressive effects arise from the FKBP12-drug complex targeting downstream proteins—calcineurin (CaN) in the case of FK506 and mammalian target of rapamycin (mTOR) with rapamycin. FKBP12 also associates with intracellular calcium release channels, including ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate receptors (IP3Rs), stabilizing their function and modulating calcium signaling. Through its interactions with CaN and these channels, FKBP12 plays a critical role in regulating calcium-dependent cellular processes such as muscle contraction, T-cell activation, and apoptosis.

Background

FKBP12 is a cytosolic protein belonging to the immunophilin family, ubiquitously expressed in all tissues and functions primarily as a peptidyl-prolyl cis/trans isomerase (PPIase), facilitating protein folding and acting as a molecular chaperone. Structurally, FKBP12 contains a single PPIase domain with a compact globular fold and a hydrophobic pocket that binds natural substrates and immunosuppressive drugs such as FK506 and rapamycin. Although drug binding inhibits its PPIase activity, the immunosuppressive effects arise from the FKBP12-drug complex targeting downstream proteins—calcineurin (CaN) in the case of FK506 and mammalian target of rapamycin (mTOR) with rapamycin. FKBP12 also associates with intracellular calcium release channels, including ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate receptors (IP3Rs), stabilizing their function and modulating calcium signaling. Through its interactions with CaN and these channels, FKBP12 plays a critical role in regulating calcium-dependent cellular processes such as muscle contraction, T-cell activation, and apoptosis.

References
https://pubmed.ncbi.nlm.nih.gov/25986568/

Reference Table for Selecting PVDF Membrane Pore Size Specifications

Protein Size (kDa)	PVDF Transfer Membrane Pore Size (μm)
< 10	0.22
10-20	0.22
20-30	0.45
30-45	0.45
45-70	0.45
80-100	0.45
100-140	0.45
> 140	0.45

Tech Support

Answers to questions you may have can be found in the inhibitor handling instructions. Topics include how to prepare stock solutions, how to store inhibitors, and issues that need special attention for cell-based assays and animal experiments.

Handling Instructions

Tel: +1-832-582-8158 Ext:3
If you have any other enquiries, please leave a message.

* Indicates a Required Field

Protein Size (kDa)	Separating Gel Percentage
4-40	20%
12-45	15%
10-70	12.5%
15-100	10%
25-100	8%
60-210	5%