Functional Differences Between Endopeptidases and Exopeptidases and Their Applications in Disease Mechanism Research
Functional Differences Between Endopeptidases and Exopeptidases and Their Applications in Disease Mechanism Research
Endopeptidases and exopeptidases act on internal and terminal regions of peptide chains, respectively. They are important enzyme classes in protein degradation, peptide processing, antigen presentation, cell death, and disease microenvironment research. The two differ clearly in substrate level, cleavage outcome, and mechanistic interpretation in disease studies.
Keywords: endopeptidase; exopeptidase; protein degradation; peptide processing; aminopeptidase; carboxypeptidase; dipeptidyl peptidase
1 Protease Cleavage Sites and Functional Boundaries
1.1 Basic Differences Between Endopeptidases and Exopeptidases
Proteases can be classified by cleavage site into endopeptidases and exopeptidases. Endopeptidases cleave peptide bonds inside proteins or peptides, often causing substrate fragmentation, domain release, or generation of functional fragments. Exopeptidases progressively remove amino acids or short peptides from the N-terminus or C-terminus of peptide chains, mainly affecting terminal structure, peptide length, activity, and degradation fate.
Table 1 Core Differences Between Endopeptidases and Exopeptidases
Comparison Dimension | Endopeptidases | Exopeptidases |
Cleavage site | Internal peptide bonds | N-terminus or C-terminus of peptide chains |
Typical substrates | Intact proteins, large polypeptides, ECM proteins, membrane proteins | Polypeptides, oligopeptides, short peptides, terminally modified peptides |
Direct outcome | Primary cleavage, domain release, functional fragment generation | Terminal trimming, short peptide clearance, maturation, or inactivation |
Detection focus | Cleavage fragments, substrate degradation, protein structural changes | Terminal substrate hydrolysis, released products, peptide length changes |
Research directions | Apoptosis, ECM remodeling, coagulation/fibrinolysis, tissue injury | Antigen peptide processing, bioactive peptide regulation, short peptide clearance, immunometabolism |
1.2 Cleavage Site and Catalytic Mechanism
Cleavage site and catalytic mechanism are two different classification dimensions. Cleavage site determines whether a protease is an endopeptidase or an exopeptidase, while catalytic mechanism determines the enzymatic reaction mode, metal ion dependence, and inhibitor sensitivity. Among metalloproteases, MMPs are endopeptidases, whereas aminopeptidases, carboxypeptidases, ACE, DPP3, and CNDP2 are exopeptidases or exopeptidase-related members. Among cysteine proteases, caspases and some cathepsins mainly function through internal cleavage, whereas Cathepsin C/DPPI has N-terminal dipeptide-removing activity.
Table 2 Protease Catalytic Types and Representative Directions
Catalytic Type | Representative Endopeptidases | Representative Exopeptidases | Research Notes |
Serine proteases | Trypsin, thrombin, plasmin | DPP4, DPP7, TPP2, and others | Digestive enzymes, coagulation/fibrinolysis, immunometabolism, and short peptide processing |
Cysteine proteases | Caspases, Cathepsin B/L/S | Cathepsin C/DPPI | Apoptosis, inflammatory cell death, lysosomal function, and immune effector enzyme maturation |
Aspartic proteases | Pepsin, Cathepsin D, Renin | A few related exopeptidases | Acidic protein degradation, blood pressure regulation, and lysosomal research |
Metalloproteases | MMPs, ADAMs, Neprilysin | Aminopeptidases, carboxypeptidases, ACE, DPP3, CNDP2 | ECM remodeling, vasoactive peptide regulation, and terminal peptide processing |
Threonine proteases | Proteasome catalytic subunits | - | Proteostasis, antigen peptide generation, and cell cycle regulation |
2 Endopeptidase-Mediated Protein Cleavage Events
2.1 Internal Protein Cleavage and Fragment Generation
Endopeptidases alter substrate structure by cleaving internal peptide bonds within proteins or polypeptides. MMPs can cleave collagen, gelatin, and various extracellular matrix components. ADAMs can shed membrane proteins, receptors, or ligands. Caspases cleave apoptosis-related substrates. Cathepsins participate in lysosomal degradation and antigen processing. The proteasome cleaves ubiquitinated proteins into polypeptides or antigen peptide precursors. The core of endopeptidase research is to confirm substrate cleavage events and their downstream functional outcomes.
(1) ECM and membrane protein cleavage
MMP- and ADAM-mediated cleavage is often associated with tumor invasion, inflammatory cell migration, vascular remodeling, and tissue repair. Such studies usually require combined analysis of matrix degradation, membrane protein shedding products, and cell migration phenotypes.
(2) Intracellular substrate cleavage
Caspases, the proteasome, and lysosomal cathepsins participate in cell death, proteostasis, and antigen processing. Related detection should focus on cleavage fragments, substrate consumption, and changes in pathway markers.
2.2 Disease Research Directions of Endopeptidases
In disease mechanisms, endopeptidases often correspond to structural disruption, signal release, and cascade initiation. Abnormal MMP and cathepsin activity can indicate enhanced ECM remodeling or tissue invasion. Caspase activation can support apoptosis or inflammatory cell death processes. ADAM-mediated membrane protein shedding can affect receptor signaling and inflammatory amplification. Renin, thrombin, and plasmin are associated with humoral regulation, coagulation/fibrinolysis, and vascular responses.
Table 3 Major Endopeptidase Types and Application Directions
Endopeptidase Type | Representative Members | Main Action | Disease Research Direction |
Serine endopeptidases | Trypsin, chymotrypsin, thrombin, plasmin, elastase | Internal protein cleavage, coagulation/fibrinolysis, tissue protein degradation | Digestion, coagulation/fibrinolysis, inflammatory tissue injury |
Matrix metalloproteinases | MMP2, MMP9, MMP13 | ECM degradation and matrix remodeling | Tumor invasion, inflammation, fibrosis, vascular remodeling |
ADAM family | ADAM10, ADAM17 | Membrane protein shedding and receptor or ligand release | Inflammatory signaling, tumor microenvironment, receptor pathway regulation |
Caspase family | Caspase-3, Caspase-8, Caspase-9 | Cleavage of apoptotic substrates | Cell death, tissue injury, drug-induced apoptosis |
Cathepsin family | Cathepsin B/D/L/S | Lysosomal degradation and antigen processing | Neurodegenerative diseases, inflammation, tumor invasion |
Proteasome | β1, β2, β5 catalytic subunits | Ubiquitinated protein cleavage | Proteostasis, antigen peptide generation, tumor therapy |
Renin | Renin | Angiotensinogen cleavage | Hypertension, kidney disease, cardiovascular regulation |
3 Exopeptidase-Mediated Terminal Peptide Processing
3.1 Cleavage Direction of Exopeptidases
The function of exopeptidases is determined by cleavage direction and removal unit. N-terminal exopeptidases process peptides from the amino terminus and include aminopeptidases, dipeptidyl peptidases, and tripeptidyl peptidases. C-terminal exopeptidases process peptides from the carboxyl terminus and include carboxypeptidases and peptidyl dipeptidases. N-terminal processing often affects antigen presentation, chemokine activity, incretin stability, and short peptide clearance. C-terminal processing often participates in neuropeptide maturation, coagulation and inflammatory regulation, complement-related peptide processing, and vasoactive peptide processing.
Table 4 Exopeptidase Types and Research Positioning
Exopeptidase Type | Cleavage Direction | Removal Unit | Representative Members | Research Directions |
Aminopeptidases | N-terminus | Single amino acid | LAP, APN/CD13, ERAP1, ERAP2, LAP3, NPEPPS, MetAP1/2, ENPEP | N-terminal trimming, antigen peptide processing, short peptide clearance |
Carboxypeptidases | C-terminus | Single amino acid | CPA, CPB, CPE, CPN, CPM, CPZ | C-terminal maturation, neuropeptide processing, coagulation and inflammation |
Dipeptidyl peptidases | N-terminus | Dipeptide | DPP4, DPP7, DPP8, DPP9, DPP3, Cathepsin C/DPPI, GPDA | Incretin degradation, Gly-Pro substrate hydrolysis, immunometabolism, lysosomal peptide processing |
Tripeptidyl peptidases | N-terminus | Tripeptide | TPP1, TPP2 | Lysosomal degradation, cytosolic short peptide processing, nervous system diseases |
Dipeptidases | Dipeptide substrates | Hydrolysis into amino acids | DPEP1, DPEP2, CNDP1, CNDP2 | Terminal degradation of small peptides, renal and intestinal peptide metabolism |
Peptidyl dipeptidases | C-terminus | Dipeptide | ACE | Vasoactive peptide processing and renin-angiotensin system regulation |
3.2 Functional Outcomes of Terminal Processing
Exopeptidases determine the terminal fate of cleavage fragments. NPEPPS, LAP3, and TPP2 participate in cytosolic short peptide clearance. ERAP1/2 trim MHC I antigen peptides in the endoplasmic reticulum. DPP4 cleaves GLP-1, GIP, and some chemokines. DPP7, DPP3, and GPDA participate in dipeptide removal under different substrate contexts. CPE participates in neuroendocrine peptide maturation. ACE participates in vasoactive peptide processing. Exopeptidase abnormalities may manifest as short peptide accumulation, altered antigen presentation, bioactive peptide imbalance, or remodeling of local microenvironmental signaling.
4 Impact of Functional Differences on Disease Mechanism Research
4.1 Different Substrate and Product Levels
Endopeptidases often process intact proteins, large polypeptides, ECM proteins, membrane proteins, coagulation factors, or apoptotic substrates, resulting in cleavage fragments or disruption of protein structural integrity. Exopeptidases often process polypeptides, oligopeptides, short peptides, terminally modified peptides, or bioactive peptide precursors, resulting in changes in N-terminal or C-terminal structure, peptide length, and biological activity.
The two can act sequentially in the same pathway: after the proteasome generates antigen peptide precursors, ERAP1/2 perform N-terminal trimming; after cathepsins cleave lysosomal protein substrates, TPP1, Cathepsin C, and related enzymes further process short peptides; after MMPs cleave ECM proteins, local matrix-derived peptides can be further processed by exopeptidases.
4.2 Different Mechanistic Interpretation Focuses
Endopeptidases are more often used to explain structural disruption and signal release, such as ECM loosening, receptor or ligand shedding, initiation of cell death, coagulation/fibrinolysis cascade reactions, and tissue barrier disruption. Exopeptidases are more often used to explain terminal regulation, such as antigen peptide length alteration, bioactive peptide maturation or inactivation, chemokine cleavage, incretin degradation, vasoactive peptide processing, and short peptide clearance. Disease research should distinguish between the two levels of “cleavage to generate substrates” and “terminal processing of substrates.”
Table 5 Influence of Localization on Functional Interpretation of Endopeptidases and Exopeptidases
Localization | Typical Endopeptidases | Typical Exopeptidases | Mechanistic Interpretation Focus |
Cytosol | Caspases, proteasome | NPEPPS, LAP3, TPP2, DPP3, CNDP2 | Apoptosis, proteostasis, short peptide clearance |
Endoplasmic reticulum | Some antigen processing-related enzymes | ERAP1, ERAP2 | MHC I antigen peptide trimming |
Lysosome | Cathepsin B/D/L/S | TPP1, Cathepsin C/DPPI, DPP7 | Autophagy, degradation of endocytic substrates, immune effector enzyme maturation |
Cell membrane | ADAMs, membrane-type MMPs | CD13/APN, DPP4, ENPEP | Receptor shedding, extracellular peptide regulation, microenvironment remodeling |
Plasma/extracellular space | Thrombin, plasmin, MMPs | CPN, ACE, some carboxypeptidases | Coagulation/fibrinolysis, vasoactive peptides, and inflammatory regulation |
5 Application Directions in Disease Research
5.1 Tumor Invasion and Immune Escape
During tumor progression, endopeptidases and exopeptidases participate in matrix cleavage, peptide signal regulation, and altered immune recognition, respectively. MMPs, ADAMs, and cathepsins can degrade ECM or shed membrane proteins, promoting tumor cell migration and tissue infiltration. CD13/APN, DPP4, and some carboxypeptidases can regulate extracellular peptides, chemokines, and angiogenesis-related signals. ERAP1/2 affect MHC I presentation and tumor cell immune visibility by altering the antigen peptide repertoire.
5.2 Inflammatory Immunity and Cell Death
Inflammatory immunity research should distinguish protein cleavage, peptide processing, and immune cell responses. Caspases participate in apoptosis and inflammatory cell death. Cathepsins participate in lysosomal antigen processing. ERAP1/2 participate in MHC I antigen peptide trimming. DPP4 can alter the activity of some chemokines. Cathepsin C participates in the maturation of proteases related to neutrophil and cytotoxic immune effector functions.
5.3 Metabolic, Cardiovascular, and Nervous System Diseases
In metabolic, cardiovascular, and nervous system diseases, proteases mainly function in bioactive peptide regulation, proteostasis, and tissue injury. DPP4 affects incretin signaling by cleaving GLP-1 and GIP. IRAP is related to insulin-associated vesicle trafficking and glucose uptake. Renin initiates angiotensinogen cleavage, and ACE participates in angiotensin system regulation. The proteasome, cathepsins, NPEPPS, TPP1, TPP2, and CNDP2 can affect protein aggregation, lysosomal degradation, short peptide clearance, and neuropeptide homeostasis.
Table 6 Application Directions of Endopeptidases and Exopeptidases in Disease Mechanisms
Disease Direction | Related Endopeptidases | Related Exopeptidases | Mechanistic Nodes | Recommended Detection |
Tumor invasion | MMPs, ADAMs, cathepsins | CD13/APN, DPP4 | ECM degradation, migration, microenvironment signaling | IHC, enzyme activity, migration/invasion assays, matrix degradation indicators |
Tumor immunity | Proteasome, cathepsins | ERAP1/2, TPP2 | Antigen generation and antigen peptide trimming | MHC I, antigen presentation, T cell recognition |
Inflammatory immunity | Caspases, cathepsins | DPP4, Cathepsin C, ERAP1/2 | Cell death, chemokine cleavage, immune effector enzyme maturation | Inflammatory factors, immune cell infiltration, lysosomal indicators |
Glucose metabolism abnormalities | - | DPP4, IRAP | Incretin degradation, insulin-related vesicle trafficking | DPP4 activity, GLP-1, GIP, insulin signaling |
Cardiovascular regulation | Renin, MMPs | ACE, CPN, ENPEP | Vasoactive peptide processing, vascular remodeling | Angiotensin-related indicators, blood pressure, endothelial markers |
Neurodegenerative diseases | Cathepsins, proteasome | NPEPPS, TPP1, TPP2, CNDP2 | Protein aggregation, short peptide clearance, lysosomal function | Aβ, Tau, LC3, p62, LAMP1/2 |
Kidney and intestinal injury | MMPs, cathepsins | CD13, ENPEP, DPP4, DPEP, CNDP | Epithelial injury, local peptide metabolism, inflammatory response | KIM-1, NGAL, barrier indicators, enzyme activity detection |
6 Experimental Design and Result Interpretation
6.1 Relationship Among Expression, Activity, and Substrate Results
Protease research needs to distinguish expression, activity, and substrate results. qPCR, Western blot, ELISA, and immunohistochemistry are used to assess target protease level and localization. Enzyme activity assays are used to evaluate functional status. Substrate or product changes connect enzyme activity with biological phenotypes. Endopeptidase research focuses on protein substrate degradation, cleavage fragments, gelatin zymography, and ECM degradation products. Exopeptidase research focuses on terminal substrate hydrolysis, such as Leu-AMC, Leu-pNA, and Gly-Pro-AMC, as well as bioactive peptide levels, antigen peptide length, and released product quantification.
6.2 Substrate Specificity and Member Attribution
Broad-spectrum substrates are suitable for evaluating overall protease activity, but member attribution requires further validation. Enhanced gelatin zymography signals may indicate changes in gelatinase-related activity, but MMP2, MMP9, or other gelatinases should be distinguished. Increased Leu-AMC or Leu-pNA hydrolysis indicates increased aminopeptidase-like activity, but cannot independently be attributed to CD13, LAP3, or NPEPPS. Increased Gly-Pro-AMC hydrolysis indicates changes in DPP-related enzyme activity, but differences among DPP4, DPP7, DPP8, DPP9, DPP3, GPDA, and other members still need to be considered. Member-specific conclusions should be supported by expression detection, selective inhibition, genetic intervention, substrate changes, and functional phenotypes.
6.3 Functional Intervention Validation
Inhibitors can be used to determine enzyme activity dependence, while gene knockdown, overexpression, CRISPR editing, and rescue experiments can be used for causal validation. In endopeptidase research, if inhibition of MMPs, caspases, or cathepsins synchronously reduces substrate cleavage, pathway activation, and pathological phenotype, their mechanistic role is supported. In exopeptidase research, if intervention targeting DPP4, DPP7, DPP3, ERAP1/2, TPP2, or CNDP2 synchronously changes bioactive peptide levels, antigen presentation, short peptide clearance, or cellular phenotypes, the mechanistic conclusion is strengthened.
7 Related Products
Table 7 Representative Endopeptidase and Exopeptidase Enzyme Products
Module | Product Name | CAS No. | Precise Classification | Application Positioning |
Endopeptidase | Trypsin | Serine endopeptidase | For internal protein cleavage, protein digestion, and endopeptidase activity control | |
Endopeptidase | α-Chymotrypsin | Serine endopeptidase | For cleavage near aromatic amino acids and protein digestion research | |
Endopeptidase | Thrombin | Serine endopeptidase | For coagulation cascade, fibrin formation, and plasma protein cleavage research | |
Endopeptidase | Plasmin | Serine endopeptidase | For fibrin degradation, fibrinolytic system, and tissue remodeling research | |
Endopeptidase | Elastase | Serine endopeptidase | For elastin degradation, inflammatory tissue injury, and pulmonary disease mechanism research | |
Endopeptidase | Pepsin | Aspartic endopeptidase | For internal protein cleavage under acidic conditions and digestive enzyme model research | |
Endopeptidase | Papain | Cysteine endopeptidase | For protein hydrolysis, enzymology controls, and tissue processing-related research | |
Endopeptidase | Proteinase K | Serine endopeptidase | For broad-spectrum protein degradation, nucleic acid extraction, and protein digestion treatment | |
Endopeptidase | Collagenase | Metalloprotease-type endopeptidase preparation | For collagen degradation, ECM cleavage, and tissue digestion research | |
Endopeptidase | Thermolysin | Metalloendopeptidase | For metalloprotease reactions, peptide cleavage, and endopeptidase enzymology controls | |
Endopeptidase | Cathepsin D | Aspartic endopeptidase | For lysosomal protein degradation, neurodegenerative disease, and tumor mechanism research | |
Exopeptidase | Leucine aminopeptidase, LAP | Aminopeptidase, N-terminal single amino acid removal | For LAP enzymology research, N-terminal amino acid removal, and methodological controls | |
Exopeptidase | Aminopeptidase M | Aminopeptidase M / membrane-associated aminopeptidase | For membrane-type aminopeptidase-related enzymatic experiments, N-terminal peptide trimming, and activity controls | |
Exopeptidase | Cathepsin C / DPPI | Dipeptidyl peptidase I, N-terminal dipeptide removal | For lysosomal exopeptidase activity, N-terminal dipeptide removal, and immune effector enzyme maturation research | |
Exopeptidase | Glycyl-proline dipeptidyl aminopeptidase, GPDA | Dipeptidyl aminopeptidase / DPP-type exopeptidase | For Gly-Pro substrate hydrolysis, N-terminal dipeptide removal, and DPP-related enzymology controls | |
Exopeptidase | Carboxypeptidase A | Carboxypeptidase, C-terminal single amino acid removal | For C-terminal peptide processing, carboxypeptidase enzymatic reactions, and peptide terminal analysis | |
Exopeptidase | Carboxypeptidase B | Carboxypeptidase, C-terminal basic amino acid removal | For C-terminal Lys/Arg residue removal, peptide processing, and enzymology controls | |
Exopeptidase | Angiotensin-converting enzyme, ACE | Peptidyl dipeptidase, C-terminal dipeptide release | For vasoactive peptide processing, RAAS pathway, and cardiovascular mechanism research |
Table 8 Products Related to Protease Target Detection and Functional Research
Module | Cat. No. | Product Name | Grade & Purity | Target/Precise Classification | Application Positioning |
Endopeptidase recombinant protein | Recombinant Human MMP2 Protein | ≥90%(SDS-PAGE) | MMP2, matrix metalloendopeptidase | For MMP2-related ECM degradation, gelatin degradation, and tumor invasion mechanism research | |
Endopeptidase recombinant protein | Recombinant Human MMP2 Protein | ≥90%(SDS-PAGE) | MMP2, matrix metalloendopeptidase | For MMP2 enzymatic reactions, substrate cleavage, and matrix remodeling research | |
Endopeptidase recombinant protein | Recombinant Human MMP2 Protein | ≥95%(SDS-PAGE) | MMP2, matrix metalloendopeptidase | For high-purity MMP2-related substrate cleavage, inhibitor screening, and mechanism validation | |
Endopeptidase antibody | Recombinant MMP2 Antibody | Recombinant, ExactAb™, Validated, See COA | MMP2, matrix metalloendopeptidase | For MMP2 expression detection, tumor invasion, and ECM remodeling research | |
Endopeptidase antibody | Recombinant MMP26 Antibody | Recombinant, ExactAb™, Validated, 0.3 mg/mL | MMP26, matrix metalloendopeptidase | For MMP26 expression detection, epithelial tissue remodeling, and tumor-related protease research | |
Endopeptidase recombinant protein | Recombinant Mouse MMP2 Protein | ≥90%(SDS-PAGE) | MMP2, matrix metalloendopeptidase | For mouse-system MMP2 functional research and ECM degradation mechanism analysis in animal models | |
Endopeptidase antibody | MMP9 antibody | Recombinant, ExactAb™, Validated, See COA | MMP9, matrix metalloendopeptidase | For MMP9 expression detection, inflammatory infiltration, gelatin degradation, and tissue injury research | |
Endopeptidase recombinant protein | Recombinant Human MMP9 Protein | Animal Free, Carrier Free, Bioactive, ActiBioPure™, Azide Free, High Performance, His Tag, ≥95%(SDS-PAGE) | MMP9, matrix metalloendopeptidase | For MMP9 enzymatic reactions, matrix degradation, inhibitor screening, and tumor invasion research | |
Endopeptidase detection kit | Mouse Matrix MetalloProteinase 9 (MMP9) ELISA Kit | BioReagent | MMP9, detection target of matrix metalloendopeptidase | For detecting MMP9 levels in mouse samples and assisting in the evaluation of inflammation-, tissue remodeling-, and tumor invasion-related changes | |
Endopeptidase recombinant protein | Recombinant Human ADAM10 Protein | ≥90%(SDS-PAGE) | ADAM10, membrane protein shedding-related metalloendopeptidase | For ADAM10-mediated membrane protein shedding, receptor regulation, and inflammatory signaling research | |
Endopeptidase recombinant protein | Recombinant Human ADAM10 Protein | Carrier Free, His Tag, ≥90%(SDS-PAGE), expressed in E. coli; See COA | ADAM10, membrane protein shedding-related metalloendopeptidase | For ADAM10-related substrate shedding, receptor/ligand release, and mechanism validation | |
Endopeptidase detection kit | Human A Disintegrin And Metalloprotease 10 (ADAM10) ELISA Kit | BioReagent | ADAM10, detection target of membrane protein shedding-related metalloendopeptidase | For detecting ADAM10 levels in human samples and assisting in the analysis of membrane protein shedding and inflammatory signaling changes | |
Endopeptidase detection kit | Rat A Disintegrin And Metalloprotease 10 (ADAM10) ELISA Kit | BioReagent | ADAM10, detection target of membrane protein shedding-related metalloendopeptidase | For detecting ADAM10 levels in rat samples; suitable for tissue remodeling and receptor shedding research in animal models | |
Endopeptidase recombinant protein | Recombinant Human ADAM17 Protein | ≥90%(SDS-PAGE) | ADAM17, membrane protein shedding-related metalloendopeptidase | For ADAM17-mediated TNF-α release, EGFR ligand shedding, and inflammatory amplification mechanism research | |
Endopeptidase detection kit | Human A Disintegrin And Metalloprotease 17 (ADAM17) ELISA Kit | BioReagent | ADAM17, detection target of membrane protein shedding-related metalloendopeptidase | For detecting ADAM17 levels in human samples and assisting in the evaluation of inflammation-, tumor microenvironment-, and membrane protein shedding-related changes | |
Endopeptidase recombinant protein | Recombinant Human Caspase-3 Protein | ≥90%(SDS-PAGE) | Caspase-3, cysteine endopeptidase | For apoptosis execution phase research, substrate cleavage, and Caspase pathway mechanism studies | |
Endopeptidase recombinant protein | Recombinant Human Caspase-3 Protein | Carrier Free, His Tag, ≥90%(SDS-PAGE) | Caspase-3, cysteine endopeptidase | For Caspase-3 enzymatic assays, apoptotic substrate cleavage, and inhibitor validation | |
Exopeptidase recombinant protein | Recombinant Human DPPII/QPP/DPP7 Protein | Animal Free, Carrier Free, Bioactive, ActiBioPure™, His Tag, ≥95%(SDS-PAGE) | DPP7 / DPPII / QPP, dipeptidyl peptidase | For DPP7-related N-terminal dipeptide removal, intracellular/lysosomal peptide processing, and immunometabolism research | |
Exopeptidase antibody | Recombinant DPP3 Antibody | Recombinant, ExactAb™, Validated, See COA | DPP3, dipeptidyl peptidase-related target | For DPP3 expression detection, cytosolic exopeptidase function, and disease mechanism research | |
Exopeptidase recombinant protein | Recombinant Human DPP3 Protein | Carrier Free, Bioactive, ActiBioPure™, His Tag, ≥90%(SDS-PAGE), See COA | DPP3, zinc-dependent dipeptidyl peptidase | For DPP3-related peptide processing, enzymatic reactions, and exopeptidase function research | |
Exopeptidase antibody | Recombinant Tripeptidyl peptidase 2 Antibody | KD Validation | TPP2, tripeptidyl peptidase | For TPP2 protein detection, cytosolic short peptide processing, and tripeptidyl peptidase pathway research | |
Exopeptidase antibody | Recombinant Tripeptidyl peptidase II/TPPII Antibody | Recombinant, ExactAb™, Validated, 0.6 mg/mL | TPP2 / TPPII, tripeptidyl peptidase | For TPP2 expression detection, cytosolic short peptide processing, antigen processing, and nervous system disease research | |
Exopeptidase recombinant protein | Recombinant Human ERAP1 Protein | ≥90%(SDS-PAGE) | ERAP1, endoplasmic reticulum aminopeptidase | For MHC I antigen peptide N-terminal trimming, autoimmunity, and tumor immunity mechanism research | |
Exopeptidase recombinant protein | Recombinant Human Aminopeptidase LRAP/ERAP2 Protein | Animal Free, Carrier Free, Bioactive, ActiBioPure™, His Tag, ≥90%(SDS-PAGE) | ERAP2 / LRAP, endoplasmic reticulum aminopeptidase | For antigen peptide processing, MHC I presentation, and immune-related mechanism research | |
Exopeptidase antibody | Recombinant DPP4 Antibody | Recombinant, ExactAb™, Validated, See COA | DPP4 / CD26, dipeptidyl peptidase | For DPP4 expression detection, incretin degradation, inflammatory immunity, and metabolic disease research | |
Exopeptidase antibody | CNDP2 Mouse mAb | KD Validation | CNDP2, dipeptidase | For CNDP2 protein detection, intracellular dipeptide hydrolysis, and metabolic regulation research | |
Exopeptidase recombinant protein | Recombinant Human CNDP2 Protein | Carrier Free, His Tag, ≥90%(SDS-PAGE), expressed in E. coli; See COA | CNDP2, dipeptidase | For intracellular dipeptide hydrolysis, small peptide metabolism, and disease mechanism research |
8 Common Questions
8.1 What Is the Core Difference Between Endopeptidases and Exopeptidases?
The core difference is the cleavage position. Endopeptidases cleave peptide bonds inside peptide chains to generate cleavage fragments. Exopeptidases progressively remove amino acids or short peptides from the N-terminus or C-terminus to complete terminal processing, maturation, inactivation, or clearance.
8.2 What Type of Protease Is Cathepsin C?
Cathepsin C, also known as DPPI, is an N-terminal dipeptidyl peptidase that removes dipeptides from the N-terminus of polypeptides. It differs from Cathepsin B, Cathepsin L, or Cathepsin S, which mainly perform internal cleavage, and is suitable for classification under the dipeptidyl peptidase module of exopeptidases.
8.3 Are DPP3, DPP7, and DPP4 All Exopeptidase-Related Members?
Yes. DPP3, DPP4, and DPP7 are all exopeptidase-related members and participate in N-terminal dipeptide removal or dipeptidyl peptidase-related peptide processing. Different members differ in localization, catalytic mechanism, and substrate preference. Experimental interpretation should distinguish them according to target, substrate, and sample type.
Endopeptidases correspond to internal protein cleavage, while exopeptidases correspond to terminal peptide processing. Mechanism studies involving these two enzyme classes should simultaneously consider cleavage site, substrate level, enzyme localization, and functional endpoint.
For more related articles, please see below:
[1] Commonly Used Proteases in Research: Fundamentals and Representative Applications
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