Expression, Purification, and Antimicrobial Activity of S100A12

Area of Science:

• Immunology
• Microbiology
• Biochemistry

Background:

• Calgranulin proteins, including S100A12 (EN-RAGE), are crucial for innate immunity and belong to the S100 class of calcium-binding proteins.
• Certain S100 proteins exhibit high-affinity transition metal binding, contributing to nutritional immunity by sequestering metals from pathogens.
• S100A12 is abundant in innate immune cells like macrophages and neutrophils and binds zinc and copper.

Purpose of the Study:

• To refine methods for expressing, enriching, and purifying S100A12 in its active, metal-binding form.
• To investigate the antimicrobial activity of S100A12 against the bacterial pathogen Helicobacter pylori.
• To elucidate the mechanism underlying S100A12's antimicrobial effect, specifically its role in zinc binding.

Main Methods:

• Development of an optimized protocol for S100A12 expression and purification.
• Characterization of S100A12 in its active, metal-binding configuration.
• In vitro assays to assess the impact of S100A12 on bacterial growth and viability of Helicobacter pylori.

Main Results:

• A refined method for producing active, metal-binding S100A12 was established.
• S100A12 demonstrated significant antimicrobial activity against Helicobacter pylori.
• The antimicrobial activity was directly linked to S100A12's ability to bind and chelate zinc.

Conclusions:

• S100A12 exhibits antimicrobial properties against Helicobacter pylori through zinc sequestration.
• This mechanism highlights the role of S100A12 in nutritional immunity by depriving bacteria of essential nutrients.
• The findings provide insights into potential therapeutic strategies targeting bacterial nutrient acquisition.