Question

The cationic antimicrobial peptide, histatin is found in human's_____________.

• A. Synovial fluid
• B. Cerebrospinal fluid
• C. Bile juice
• D. Saliva

Hint:

Associate histatins with the oral cavity. The name itself contains "hist-" for histidine-rich and "-statin" suggesting a stopping/inhibiting action, which in this case is microbial growth in the mouth.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Antimicrobial peptides (AMPs) are a component of the innate immune system found in a wide range of organisms. They provide a rapid, non-specific defense against pathogens. Histatins are a specific family of AMPs, and the question asks for their primary location in the human body.
Step 2: Detailed Explanation:


Histatins are a family of small, cationic, histidine-rich peptides.

They are secreted exclusively by the parotid and submandibular salivary glands.

Consequently, they are a major protein component of human saliva.

Their primary functions in the oral cavity include potent antifungal activity (especially against Candida albicans), antibacterial activity, and a role in wound healing.

They are not characteristically found in synovial fluid, cerebrospinal fluid, or bile.

Step 3: Final Answer:
The antimicrobial peptide histatin is found in human saliva.