Antarctic fungus proteases generate bioactive peptides from caseinate

Area of Science:

• Biochemistry
• Food Science
• Microbiology

Background:

• Extracellular serine proteases from Antarctic microorganisms offer unique enzymatic properties.
• Casein hydrolysates are recognized for their bioactive peptide content and health benefits.

Purpose of the Study:

• To purify and characterize an extracellular serine protease from Antarctic Acremonium sp. L1-4B.
• To evaluate the antioxidant and antihypertensive potential of bovine and caprine casein hydrolysates produced by this protease.
• To identify and characterize the peptide sequences within the hydrolysates using mass spectrometry.

Main Methods:

• Purification of extracellular serine protease from Acremonium sp. L1-4B.
• Proteolysis of bovine and caprine sodium caseinate.
• In vitro assays for antioxidant activity (copper and iron chelation, ABTS radical scavenging) and antihypertensive potential (angiotensin-converting enzyme inhibition).
• Nano-ESI-Q-TOF-MS/MS analysis for peptide identification.

Main Results:

• Caprine casein hydrolysates exhibited higher antioxidant potential, with significant copper chelation (31.2%) and ABTS radical scavenging (67.5%) at 24h.
• Bovine casein hydrolysate (8h) showed higher iron chelation capacity (43.1%).
• All hydrolysates demonstrated antihypertensive potential, with caprine casein hydrolysates (8h) inhibiting 75% of angiotensin-converting enzyme (ACE) activity.
• Mass spectrometry identified 23 peptide sequences in bovine hydrolysate (from αS1- and β-casein) and 31 in caprine hydrolysate (from β-casein).

Conclusions:

• Low molecular weight bovine and caprine casein hydrolysates possess significant antioxidant and antihypertensive properties.
• These hydrolysates have potential applications in functional foods and nutraceuticals for preventing oxidative stress-related disorders and regulating blood pressure.
• The Antarctic protease offers a novel source for producing valuable bioactive peptides from casein.