#1 Activity

“Explore ACE protein structure on RCSB PDB & Identify active site residues” into a clear hands-on activity for your workshop.

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Activity: Exploring ACE Protein Structure & Active Site Identification

Objective

Participants will:

• Retrieve and visualize the Angiotensin-Converting Enzyme (ACE) structure from the RCSB Protein Data Bank.

• Identify its active site residues using both literature and structural visualization tools.

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Step 1 – Retrieve ACE Protein Structure

1. Go to https://www.rcsb.org

2. Search for:

   Angiotensin-Converting Enzyme
   

   or directly by PDB ID:

   • Example: 1O86 (ACE bound to inhibitor Lisinopril).

3. Open the structure page.

4. Download the PDB file (.pdb format) for use in visualization software (e.g., PyMOL, UCSF Chimera, AutoDock Tools).

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Step 2 – Visualize the Structure

1. Open the .pdb file in PyMOL or UCSF Chimera.

2. Show cartoon representation for overall protein fold.

3. Highlight ligand/inhibitor (if present, e.g., Lisinopril) to locate the binding site.

4. Zoom in to observe pocket topology.

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Step 3 – Identify Active Site Residues from Literature

1. Open Google Scholar or PubMed.

2. Search:

   ACE active site residues
   

3. Example findings from literature:

   • Zinc-binding motif: His383, His387, Glu411

   • Hydrogen bond interactions: Glu384, Tyr520, Lys511

   • Hydrophobic pocket: Phe457, Val518

4. Cross-check with ligand interaction in PDB structure.

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Step 4 – Annotate in Visualization Tool

1. In PyMOL/Chimera:

   • Select residues by number.

   • Color them distinctly (e.g., red for catalytic residues, yellow for hydrophobic residues).

   • Label them with residue name and number.

2. Take screenshots for workshop records.

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Step 5 – Workshop Deliverable

Each participant should:

• Save a snapshot image showing the ACE structure, ligand, and highlighted active site residues.

• Prepare a short note listing:

  • PDB ID used.

  • Active site residues identified.

  • Any differences between their observation and literature.

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✅ Tip for Engagement:
You can provide a partial list of known ACE residues and challenge participants to find the missing ones using the structure.

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