SMCR7L/MID51 Antibody (Mouse mAb) [L21F3]

Application: Reactivity: Mouse, Rat, Human

Lane 1: LNCaP, Lane 2: 293T, Lane 3: HeLa, Lane 4: Jurkat

Experiment Essentials

WB
Recommended WB dilution ratio: 1:10000

Usage Information

Dilution
WB1:5000-1:50000 IHC1:250-1:1000 IF1:200-1:800

Application
WB, IHC, IF

Reactivity
Mouse, Rat, Human

Source
Mouse Monoclonal Antibody

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
51 kDa 48-51 kDa
^*Why do the predicted and actual molecular weights differ? The following reasons may explain differences between the predicted and actual protein molecular weight. Post-translational modifications(e.g., phosphorylation, glycosylation); Splice variants and isoforms; Relative charge; Multimerization.

Positive Control	Mouse testis tissue; Rat heart tissue; Rat kidney tissue; Rat liver tissue; Human pancreas cancer tissue; Mouse kidney tissue; Mouse liver tissue; LNCaP cells; HeLa cells; HEK-293 cells; Jurkat cells; K-562 cells; PC-12 cells; HSC-T6 cells; NIH/3T3 cells; 4T1 cells
Negative Control

Experimental Methods

WB
Experimental Protocol: Sample preparation 1. Tissue: Lyse the tissue sample by adding an appropriate volume of ice-cold RIPA Lysis Buffer (containing Protease Inhibitor Cocktail)，and homogenize the tissue at a low temperature or lyse it by sonication on ice, then incubate on ice for 30 minutes. 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 Lysis Buffer (containing Protease Inhibitor Cocktail) , sonicate to lyse the cells, and incubate on ice for 30 minutes. 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 Lysis Buffer (containing Protease Inhibitor Cocktail) , sonicate to lyse the cells, and incubate on ice for 30 minutes. 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: 10%. 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. ( 0.45 µm PVDF membrane is recommended ) Reference Table for Selecting PVDF Membrane Pore Size Specifications Recommended conditions for wet transfer: 200 mA, 120 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 primary antibody dilution buffer to prepare the primary antibody working liquid (recommended dilution ratio for primary antibody 1:10000), 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.

WB

Experimental Protocol:

Sample preparation

1. Tissue: Lyse the tissue sample by adding an appropriate volume of ice-cold RIPA Lysis Buffer (containing Protease Inhibitor Cocktail)，and homogenize the tissue at a low temperature or lyse it by sonication on ice, then incubate on ice for 30 minutes.

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 Lysis Buffer (containing Protease Inhibitor Cocktail) , sonicate to lyse the cells, and incubate on ice for 30 minutes.

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 Lysis Buffer (containing Protease Inhibitor Cocktail) , sonicate to lyse the cells, and incubate on ice for 30 minutes.

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: 10%. 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. ( 0.45 µm PVDF membrane is recommended ) Reference Table for Selecting PVDF Membrane Pore Size Specifications

Recommended conditions for wet transfer: 200 mA, 120 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 primary antibody dilution buffer to prepare the primary antibody working liquid (recommended dilution ratio for primary antibody 1:10000), 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: 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.

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.

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.

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.

Datasheet & SDS

Biological Description

Specificity
SMCR7L/MID51 Antibody (Mouse mAb) [L21F3] detects endogenous levels of total SMCR7L/MID51 protein.

Subcellular Location
Membrane, Mitochondrion, Mitochondrion outer membrane

Uniprot ID
Q9NQG6

Clone
L21F3

Synonym(s)
SMCR7L \| 3B3G3 \| MID51 \| MIEF1 \| SMCR7-like protein

Background
SMCR7L, also known as MiD51 or MIEF1, is a mitochondrial outer membrane protein of the dynamin receptor family that regulates mitochondrial morphology by controlling the recruitment and activity of the fission mediator dynamin‑related protein 1 (Drp1), thereby modulating the balance between mitochondrial fission and fusion and influencing organelle distribution, bioenergetics and stress responses. The protein contains an N‑terminal single‑pass transmembrane segment that anchors it to the outer mitochondrial membrane and a C‑terminal cytosolic domain that adopts a variant nucleotidyltransferase fold lacking catalytic activity but retaining a structured pocket that binds ADP with high affinity and GDP with lower affinity; this fold functions as a protein–protein interaction platform rather than an enzyme, providing surfaces for Drp1 engagement and regulatory interfaces that link nucleotide binding to conformational changes. MiD51 acts as a receptor for Drp1 by promoting its recruitment and association to the mitochondrial surface independently of other fission adaptors such as FIS1 and MFF, and structural and biophysical analyses show that ADP binding to MiD51 is required to stimulate Drp1 GTPase activity and assembly into long spiral tubules around mitochondria, whereas in the absence of bound ADP MiD51 inhibits Drp1 GTPase activity and favors less productive oligomeric states, indicating that MiD51 integrates nucleotide status into the control of Drp1‑mediated constriction and scission. Interaction between Drp1 and MiD51 is further regulated by the GTP loading and polymerization state of Drp1, and mutational mapping identifies two regions on MiD51 that directly bind Drp1 together with a requirement for MiD51 dimerization, dependent on residue C452, to support effective regulation of mitochondrial dynamics, establishing a multi‑interface mechanism in which MiD51 oligomerization and Drp1 filament formation cooperate to define sites and efficiency of fission events. Functional studies of MiD51 in vertebrate cells show that elevated MiD51 expression leads to pronounced changes in mitochondrial distribution and can result in elongated, fused tubules, whereas depletion causes fragmentation, supporting the view that MiD51 has a context‑dependent role in organizing fission complexes and restraining excessive fission, and that it contributes to the maintenance of healthy mitochondrial networks required for energy homeostasis, calcium handling and survival under metabolic and oxidative stress. In pancreatic islets and β‑cell lines, MiD51 is important for maintaining mitochondrial health during glucose‑stimulated insulin secretion, and altered MiD51 expression or function perturbs mitochondrial dynamics, impairs ATP generation and disrupts insulin release, connecting MiD51‑regulated fission machinery to endocrine cell function and type 2 diabetes‑related β‑cell dysfunction. MiD51 has also been implicated in cardiomyocyte physiology, neuronal development and viral immune evasion, including interactions with hepatitis C virus that affect mitochondrial morphology and antiviral signaling, suggesting that dysregulated MiD51 activity can lead to fragmented mitochondria, compromised bioenergetics and increased susceptibility to apoptosis in disease states.

Background

SMCR7L, also known as MiD51 or MIEF1, is a mitochondrial outer membrane protein of the dynamin receptor family that regulates mitochondrial morphology by controlling the recruitment and activity of the fission mediator dynamin‑related protein 1 (Drp1), thereby modulating the balance between mitochondrial fission and fusion and influencing organelle distribution, bioenergetics and stress responses. The protein contains an N‑terminal single‑pass transmembrane segment that anchors it to the outer mitochondrial membrane and a C‑terminal cytosolic domain that adopts a variant nucleotidyltransferase fold lacking catalytic activity but retaining a structured pocket that binds ADP with high affinity and GDP with lower affinity; this fold functions as a protein–protein interaction platform rather than an enzyme, providing surfaces for Drp1 engagement and regulatory interfaces that link nucleotide binding to conformational changes. MiD51 acts as a receptor for Drp1 by promoting its recruitment and association to the mitochondrial surface independently of other fission adaptors such as FIS1 and MFF, and structural and biophysical analyses show that ADP binding to MiD51 is required to stimulate Drp1 GTPase activity and assembly into long spiral tubules around mitochondria, whereas in the absence of bound ADP MiD51 inhibits Drp1 GTPase activity and favors less productive oligomeric states, indicating that MiD51 integrates nucleotide status into the control of Drp1‑mediated constriction and scission. Interaction between Drp1 and MiD51 is further regulated by the GTP loading and polymerization state of Drp1, and mutational mapping identifies two regions on MiD51 that directly bind Drp1 together with a requirement for MiD51 dimerization, dependent on residue C452, to support effective regulation of mitochondrial dynamics, establishing a multi‑interface mechanism in which MiD51 oligomerization and Drp1 filament formation cooperate to define sites and efficiency of fission events. Functional studies of MiD51 in vertebrate cells show that elevated MiD51 expression leads to pronounced changes in mitochondrial distribution and can result in elongated, fused tubules, whereas depletion causes fragmentation, supporting the view that MiD51 has a context‑dependent role in organizing fission complexes and restraining excessive fission, and that it contributes to the maintenance of healthy mitochondrial networks required for energy homeostasis, calcium handling and survival under metabolic and oxidative stress. In pancreatic islets and β‑cell lines, MiD51 is important for maintaining mitochondrial health during glucose‑stimulated insulin secretion, and altered MiD51 expression or function perturbs mitochondrial dynamics, impairs ATP generation and disrupts insulin release, connecting MiD51‑regulated fission machinery to endocrine cell function and type 2 diabetes‑related β‑cell dysfunction. MiD51 has also been implicated in cardiomyocyte physiology, neuronal development and viral immune evasion, including interactions with hepatitis C virus that affect mitochondrial morphology and antiviral signaling, suggesting that dysregulated MiD51 activity can lead to fragmented mitochondria, compromised bioenergetics and increased susceptibility to apoptosis in disease states.

References
https://pubmed.ncbi.nlm.nih.gov/24515348/ https://pubmed.ncbi.nlm.nih.gov/21508961/

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

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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%