Recombinant Human REG I&amp;lt;i&amp;gt;α&amp;lt;/i&amp;gt; Aggregates &amp;lt;i&amp;gt;Staphylococcus aureus&amp;lt;/i&amp;gt;—Exhibits a Lectin-Like Function

Nausheen Jamal,Koji Nata,Takamasa Nonaka,Kazuaki Ohashi,Yuichiro Kezuka

doi:10.4236/abb.2017.83006

Abstract

Staphylococcus aureus is pathogenic to humans with worldwide health care concern due to its ability to evade the immune system and develop resistance to multiple drugs. Reg family proteins are C-type lectins with antimicrobial properties. Bacterial aggregation through binding to microbial cell surface sugar and/or lipid moieties is key mechanism employed in the process. In the present study we have analysed the antimicrobial effect of human REG Iα on S. aureus. Aggregation of mid-log phase culture of S. aureus was observed in presence of purified recombinant REG Iα. Therefore REG Iα can be applied in eliminating S. aureus infections in humans.

Highlights

Staphylococcus aureus continues to pose a challenge to human health owing to its ability to evade the immune system by acquiring novel genetic elements and developing resistance to antibiotics [1]
Role of Class III Reg family proteins in aggregation followed by killing of bacteria such as Salmonella, Yersinia, Listeria and Enterococcus is documented [16] [17] [19] [20]
In the present study we examined the antimicrobial effect of human REG Iα against S. aureus which is a class I Reg family member

Summary

Introduction

Staphylococcus aureus continues to pose a challenge to human health owing to its ability to evade the immune system by acquiring novel genetic elements and developing resistance to antibiotics [1]. Class III Reg family proteins show antibacterial activity against Salmonella Typhimurium, Yersinia pseudituberculosis, Bacillus subtilis, Enterococcus faecalis, Listeria innocua and L. monocytogens [15]-[20] owing to their ability to bind to molecules displayed on bacterial cell surfaces [15] [16] [20] [21]. Amino acid sequence and structure analyses reveal a C-type lectin-like domain in human REG Iα [29] [30]. In the present study we have analysed the lectin-like properties of human REG Iα against the cell surface polysaccharides of gram-positive S. aureus. For our purpose we expressed recombinant human REG Iα in E. coli and purified the gene product from inclusion bodies, on anion exchange chromatography column and used the purified protein to analyse the stimulation of S. aureus aggregation

Expression System

Expression and Refolding of REG Iα

Anion Exchange Chromatography

Bacterial Aggregation

Results and Discussion