Digestive Enzymes

Digestive enzymes are biologically active proteins that catalyze the breakdown of macronutrients—carbohydrates, proteins, and fats—into absorbable molecules. They are secreted by the gastrointestinal tract (e.g., salivary amylase, gastric pepsin, pancreatic lipase) and function to optimize nutrient assimilation and reduce gastrointestinal stress.

• Structure: Digestive enzymes are large, single‑polypeptide proteins with molecular weights ranging from 20 kDa (e.g., bromelain) to >100 kDa (e.g., human pancreatic lipase).
• Molecular Formula: They lack a single molecular formula; instead, they are composed of thousands of atoms (e.g., a 50 kDa enzyme ≈ 450 amino‑acid residues, ~ 3 × 10⁴ Da).
• IUPAC Name: The IUPAC systematic name for a generic enzyme is [substrate]‑hydrolase (e.g., pancreatic lipase = triacylglycerol‑hydrolase, EC 3.1.1.3).
• Key Features: Key structural features include an active‑site pocket containing catalytic residues (Ser‑195, His‑57, Asp‑102 in serine proteases) or a catalytic triad in lipases (Ser‑153, Asp‑177, His‑226).
• Glycosylation: Many enzymes are glycosylated, which stabilizes them in the acidic gastric environment and influences their pH optimum (e.g., pepsin active at pH 1–3).

• Sources: Commercial digestive enzymes are derived from animal pancreas (porcine or bovine), fungi (e.g., Aspergillus niger for amylase, Rhizopus oryzae for lipase), bacterial cultures (e.g., Bacillus subtilis proteases), and plant sources (bromelain from pineapple stems, papain from papaya latex).
• Extraction: Extraction involves homogenization, followed by pH‑adjusted precipitation, ultrafiltration, and chromatographic purification to achieve >90 % activity.
• Production: Fermentation‑based production (e.g., recombinant Pichia pastoris expression of human pancreatic lipase) offers high purity and low allergenicity.
• Quality Control: Quality‑control metrics include unit activity (USP, U), protein purity (≥ 90 % SDS‑PAGE), absence of microbial contaminants, and stability testing across pH 2–8.
• Certification: Certification (e.g., GMP, USP) and third‑party testing (e.g., NSF, Informed‑Choice) are essential to ensure product consistency and safety.