GO:0070001 aspartic-type peptidase activity: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0070001 aspartic-type peptidase activity describes catalysis of peptide bond hydrolysis by a water molecule activated by two aspartic acid residues in the active site.
• Aspartic peptidases are widely distributed across fungi, parasites, and humans, where they mediate protein turnover, virulence, and disease progression.
• Fungal aspartic peptidases such as those from Candida albicans, Trichosporon asahii, and Phialophora verrucosa are established virulence factors and drug targets.
• Human aspartic peptidases, including cathepsin D and renin, are implicated in neurodegeneration, cancer, and cardiovascular disease.
• CRISPR knockout, point mutation, and knock-in models enable precise dissection of aspartic peptidase function in disease-relevant cell types.
• EDITGENE provides end-to-end CRISPR services for aspartic peptidase research, from library screening to bioinformatics analysis.
Description
Aspartic-type peptidases (EC 3.4.23) are a class of proteolytic enzymes that use two aspartic acid residues in their active site to activate a water molecule for peptide bond hydrolysis. This mechanism is distinct from serine, cysteine, or metallopeptidases and is conserved from fungi to humans. The Gene Ontology term GO:0070001 captures this molecular function, which is central to protein catabolism, pathogen virulence, and human disease. Researchers study aspartic peptidases to understand fungal pathogenesis, neurodegenerative disorders, and cancer progression. For example, secreted aspartic peptidases from Candida albicans and Trichosporon asahii degrade host proteins and facilitate tissue invasion. In humans, cathepsin D, a lysosomal aspartic peptidase, is linked to Alzheimer's disease and certain cancers. The availability of CRISPR-based tools now allows precise genetic manipulation of aspartic peptidase genes in various cell models. This article provides a comprehensive overview of GO:0070001, covering its definition, mechanism, key genes, disease relevance, and research methodologies.
aspartic-type peptidase activity At A Glance
| GO ID | GO:0070001 |
|---|---|
| GO term | aspartic-type peptidase activity |
| Ontology | molecular_function |
| Synonym | None |
| Definition | Catalysis of the hydrolysis of peptide bonds in a polypeptide chain by a mechanism in which a water molecule bound by the side chains of aspartic residues at the active center acts as a nucleophile. |
| Major function | Proteolytic cleavage of peptide bonds using an aspartate-activated water molecule |
| EC number | 3.4.23 |
| Representative enzymes | Pepsin, cathepsin D, renin, fungal secreted aspartic peptidases |
| Cellular localization | Lysosomes, secretory vesicles, extracellular space, fungal cell wall |
What Is GO:0070001?
GO:0070001 aspartic-type peptidase activity is defined as the catalysis of peptide bond hydrolysis in a polypeptide chain by a mechanism in which a water molecule, bound by the side chains of aspartic residues at the active center, acts as a nucleophile. In simpler terms, two aspartic acid residues in the enzyme's active site position and activate a water molecule to break peptide bonds in proteins.
Why Is aspartic-type peptidase activity Important in Cell Biology?
Aspartic-type peptidases are essential for diverse biological processes, including protein turnover, antigen processing, and pathogen virulence. In fungi, secreted aspartic peptidases are key virulence factors that degrade host tissues and evade immune responses, making them attractive antifungal targets. In humans, dysregulated aspartic peptidase activity contributes to neurodegeneration, cancer, and cardiovascular disorders. Understanding GO:0070001 is therefore critical for developing therapeutics and for basic research in cell biology and pathogenesis.
• Fungal aspartic peptidases are virulence factors in Candida albicans, Trichosporon asahii, and Phialophora verrucosa.
• Human cathepsin D is implicated in Alzheimer's disease and other neurodegenerative disorders.
• Aspartic peptidases are targets for HIV protease inhibitors, which also block fungal peptidases.
• They play roles in biofilm formation by multidrug-resistant fungi like Candida haemulonii.
• Aspartame toxicity may involve aspartic peptidase activity in kidney stone formation.
• Multi-omics analyses identify aspartic peptidases as druggable targets in Alzheimer's disease.
• They are used as models for studying enzyme mechanism and inhibitor design.
• CRISPR screens can identify novel aspartic peptidase substrates and regulators.
What Happens During aspartic-type peptidase activity?
Substrate Binding and Active Site Activation
In simple terms: The enzyme grabs a protein and positions it for cutting.
Aspartic peptidases bind polypeptide substrates in a cleft between two domains, each contributing an aspartic acid residue to the catalytic dyad. The two aspartates are typically at low pH, where one is protonated and the other deprotonated, creating a hydrogen-bonded network that activates a water molecule. This binding step is highly specific for peptide bonds with hydrophobic or aromatic residues on either side of the scissile bond.
Catalytic Hydrolysis of the Peptide Bond
In simple terms: Water is used to break the bond between two amino acids.
The activated water molecule attacks the carbonyl carbon of the peptide bond, forming a tetrahedral transition state stabilized by the aspartic residues. Proton transfer from the water to the leaving nitrogen completes the hydrolysis, releasing two peptide fragments. This mechanism is shared by all aspartic peptidases, including pepsin, cathepsin D, and fungal secreted enzymes.
Product Release and Enzyme Turnover
In simple terms: The cut pieces are released, and the enzyme is ready to cut again.
After hydrolysis, the peptide products diffuse away, and the enzyme returns to its resting state. The active site is regenerated for another round of catalysis. In fungal pathogens, secreted aspartic peptidases degrade host proteins extracellularly, contributing to tissue invasion.
Regulation by pH and Inhibitors
In simple terms: The enzyme works best in acidic conditions and can be blocked by drugs.
Most aspartic peptidases are active at acidic pH (e.g., in lysosomes or the stomach) and are inhibited by pepstatin A. HIV protease inhibitors such as ritonavir also block fungal aspartic peptidases, interfering with growth and biofilm formation. This pH dependence and inhibitor sensitivity are key research tools.
Key Genes Involved in GO:0070001 aspartic-type peptidase activity
The following genes encode representative aspartic-type peptidases and related proteins, with their roles and research relevance.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PEP4 (Candida albicans) | Secreted aspartic peptidase | Virulence factor, antifungal target |
| SAP1-10 (Candida albicans) | Secreted aspartic peptidases | Host tissue invasion, biofilm formation |
| CTSD (human) | Lysosomal cathepsin D | Neurodegeneration, cancer, Alzheimer's disease |
| REN (human) | Renin | Blood pressure regulation, cardiovascular disease |
| PGA3 (Aspergillus) | Aspartic peptidase | Fungal pathogenesis |
| Trichosporon asahii aspartic peptidase | 30-kDa secreted enzyme | Fungal virulence |
| Phialophora verrucosa aspartic peptidase | Secreted enzyme | Target of HIV peptidase inhibitors |
| Candida haemulonii aspartic peptidase | Biofilm-associated enzyme | Multidrug resistance |
| Fonsecaea pedrosoi aspartic peptidase | Sclerotic cell secretion | Fungal infection |
| BACE1 (human) | Beta-secretase | Alzheimer's disease |
| BACE2 (human) | Beta-secretase 2 | Alzheimer's disease, pigmentation |
| Pepsinogen A (human) | Gastric aspartic peptidase | Digestion, ulcer disease |
| Napsin A (human) | Lung aspartic peptidase | Lung cancer marker |
| Plasmepsin (Plasmodium) | Hemoglobin degradation | Malaria drug target |
| HIV protease | Viral polyprotein processing | AIDS therapy |
| Saccharomyces cerevisiae PEP4 | Vacuolar proteinase A | Model for aspartic peptidase function |
| Drosophila melanogaster cathD | Cathepsin D homolog | Developmental studies |
How Is aspartic-type peptidase activity Regulated?
Aspartic-type peptidase activity is regulated at multiple levels. In fungi, secreted aspartic peptidases are induced by environmental cues such as pH and host factors. In humans, cathepsin D is regulated by lysosomal biogenesis and mTOR signaling. HIV protease inhibitors can block fungal aspartic peptidases, suggesting cross-kingdom regulation. Additionally, pH-dependent activation and inhibitor proteins like pepstatin regulate activity.
aspartic-type peptidase activity and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| CTSD | Alzheimer's disease, cancer | CRISPR knockout in SH-SY5Y cells |
| SAP1-10 | Candida albicans virulence | Knockout in C. albicans |
| BACE1 | Alzheimer's disease | Point mutation in iPSC-derived neurons |
| Phialophora verrucosa aspartic peptidase | Fungal infection | Overexpression in fungal cells |
| Candida haemulonii aspartic peptidase | Biofilm formation | Knockout in C. haemulonii |
Fungal Infections and Virulence
Secreted aspartic peptidases from Candida albicans, Trichosporon asahii, and Phialophora verrucosa degrade host proteins and facilitate tissue invasion. Inhibitors of these enzymes reduce fungal growth and biofilm formation, highlighting their potential as antifungal targets.
Neurodegenerative Disorders
Cathepsin D (CTSD) is a lysosomal aspartic peptidase linked to Alzheimer's disease and other neurodegenerative disorders. Multi-omics analyses have identified CTSD as a druggable target in Alzheimer's disease.
Cancer and Metabolic Diseases
Aspartic peptidases such as cathepsin D and napsin A are implicated in cancer progression and as biomarkers. Aspartame toxicity may involve aspartic peptidase activity in kidney stone formation.
From aspartic-type peptidase activity-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does knockout of CTSD affect amyloid-beta clearance? | CRISPR KO in human iPSC-derived neurons |
| Can point mutation in BACE1 alter substrate specificity? | CRISPR point mutation in HEK293T cells |
| Does overexpression of fungal aspartic peptidase increase virulence? | Knock-in in Candida albicans |
| What is the role of cathepsin D in lysosomal function? | Tagged knock-in in HeLa cells |
| Can aspartic peptidase inhibitors block biofilm formation? | Overexpression in Candida haemulonii |
| Does aspartame affect aspartic peptidase activity in kidney cells? | CRISPR KO in renal epithelial cells |
How to Study the aspartic-type peptidase activity Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Fluorogenic peptide assay | Enzymatic activity | Screening inhibitors |
| Mass spectrometry | Substrate cleavage sites | Identifying natural substrates |
| CRISPR knockout screen | Gene essentiality | Identifying regulators |
| Western blot | Protein expression | Validating knockout |
| Immunofluorescence | Subcellular localization | Lysosomal trafficking |
| qRT-PCR | mRNA levels | Gene expression analysis |
| Biofilm assay | Fungal biofilm formation | Testing inhibitors |
Enzymatic Activity Assays
Aspartic peptidase activity is measured using fluorogenic or chromogenic peptide substrates, often at acidic pH. Inhibitor profiling with pepstatin A confirms enzyme class.
Proteomics and Substrate Identification
Mass spectrometry-based proteomics can identify natural substrates and cleavage sites of aspartic peptidases. This is useful for understanding fungal virulence.
CRISPR Screening and Functional Genomics
Genome-wide CRISPR knockout screens can identify genes that regulate aspartic peptidase activity or sensitivity to inhibitors. This approach is powerful for drug target discovery.
Imaging and Localization
Fluorescent tagging of aspartic peptidases allows live-cell imaging of their trafficking to lysosomes or secretion. This helps understand their role in disease.
How CRISPR Can Be Used to Study GO:0070001 aspartic-type peptidase activity
Knockout
CRISPR knockout of aspartic peptidase genes (e.g., CTSD, SAP1-10) enables loss-of-function studies to determine their role in disease and virulence. This is achieved by introducing indels in early exons, leading to frameshift and nonsense-mediated decay.
Point Mutation
CRISPR point mutation can introduce specific amino acid changes in the catalytic aspartates (e.g., D32A in pepsin) to dissect mechanism. This is useful for studying substrate specificity and inhibitor resistance.
Knock-in
Knock-in of tagged aspartic peptidases (e.g., GFP or FLAG) allows tracking of protein localization and interaction. It can also be used to express mutant variants under endogenous promoters.
Overexpression
CRISPR activation (CRISPRa) or cDNA overexpression can increase aspartic peptidase levels to study gain-of-function effects, such as enhanced virulence or drug resistance.
How EDITGENE Supports aspartic-type peptidase activity Research
Researchers studying aspartic-type peptidase activity-related genes often need to determine whether a candidate gene is causally involved in a disease or pathway. EDITGENE provides comprehensive CRISPR services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for aspartic-type peptidase activity research.
Frequently Asked Questions About aspartic-type peptidase activity
What is aspartic-type peptidase activity?
It is the catalysis of peptide bond hydrolysis by a water molecule activated by two aspartic acid residues in the active site, as defined by GO:0070001.
What genes are involved in aspartic-type peptidase activity?
Key genes include CTSD, BACE1, REN, and fungal SAP genes from Candida albicans.
What diseases are associated with aspartic-type peptidases?
They are linked to fungal infections, Alzheimer's disease, cancer, and cardiovascular disorders.
How is aspartic-type peptidase activity measured?
It is measured using fluorogenic peptide substrates and inhibitor profiling with pepstatin A.
What is the role of cathepsin D in neurodegeneration?
Cathepsin D is a lysosomal aspartic peptidase implicated in Alzheimer's disease and other neurodegenerative disorders.
Can CRISPR be used to study aspartic peptidases?
Yes, CRISPR knockout, point mutation, and knock-in models are widely used to dissect their function.
What are fungal aspartic peptidases?
They are secreted enzymes that degrade host proteins and contribute to virulence in fungi like Candida albicans.
Are aspartic peptidases drug targets?
Yes, HIV protease inhibitors also block fungal aspartic peptidases, and cathepsin D is a target in Alzheimer's disease.
What is the mechanism of aspartic peptidase catalysis?
Two aspartic acid residues activate a water molecule that attacks the peptide bond, forming a tetrahedral intermediate.
How can I create a knockout of an aspartic peptidase gene?
EDITGENE provides CRISPR knockout services for aspartic peptidase genes in various cell types.
Conclusion
GO:0070001 aspartic-type peptidase activity is a fundamental molecular function with broad relevance to fungal pathogenesis, neurodegeneration, and cancer. Understanding its mechanism and regulation is essential for developing new therapeutics. EDITGENE offers a full suite of CRISPR services to accelerate research on aspartic peptidases, from knockout to overexpression and library screening.
References
- 1. Palmeira VF et al.. 2018. Fonsecaea pedrosoi Sclerotic Cells: Secretion of Aspartic-Type Peptidase and Susceptibility to Peptidase Inhibitors.. Front Microbiol 9:1383 PMID: 30008700
- 2. Granato MQ et al.. 2020. Aspartic peptidase of Phialophora verrucosa as target of HIV peptidase inhibitors: blockage of its enzymatic activity and interference with fungal growth and macrophage interaction.. J Enzyme Inhib Med Chem 35(1):629-638 PMID: 32037904
- 3. Valle RS et al.. 2017. Trichosporon asahii secretes a 30-kDa aspartic peptidase.. Microbiol Res 205:66-72 PMID: 28942846
- 4. Xu K et al.. 2025. Analysis of toxicity and mechanisms of aspartame in kidney stones with network toxicology and molecular docking strategy.. Sci Rep 15(1):45563 PMID: 41310176
- 5. Vidoni C et al.. 2016. The Role of Cathepsin D in the Pathogenesis of Human Neurodegenerative Disorders.. Med Res Rev 36(5):845-70 PMID: 27114232
- 6. Lima JC et al.. 2025. Biofilm production by the multidrug-resistant fungus Candida haemulonii is affected by aspartic peptidase inhibitor.. AIMS Microbiol 11(1):228-241 PMID: 40161246
- 7. Liu S et al.. 2025. Multi-Omics Analysis for Identifying Cell-Type-Specific Druggable Targets in Alzheimer's Disease.. medRxiv PMID: 39830273
- 8. Braga-Silva LA et al.. 2011. Aspartic protease inhibitors as potential anti-Candida albicans drugs: impacts on fungal biology, virulence and pathogenesis.. Curr Med Chem 18(16):2401-19 PMID: 21568917
