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Updated: Jun 11, 2026
Transient Expression and Cellular Localization of Recombinant Proteins in Cultured Insect Cells
Published on: April 20, 2017
A promising broad spectrum antimicrobial red fluorescent protein present in silkworm excreta
Kalyankumar Marikallappa Matti1, Chandrashekhar Jagadeeshshastri Savanurmath, Shivayogeppa Bangareppa Hinchigeri
1Department of Biochemistry, Karnatak University, Dharwad-580003, India.
Abstract:
The purified silkworm excretory red fluorescent protein (SE-RFP) has exhibited a potent broad spectrum antimicrobial activity. The anti-microbial assays of purified SE-RFP against several pathogenic bacterial (both Gram positive and Gram negative) and fungal strains were performed by agar cup plate method. The minimum inhibitory concentration (MIC) of SE-RFP against pathogenic bacteria and fungi was evaluated by agar dilution technique. The SE-RFP has exhibited highest activity (lowest minimum inhibitory concentration and largest zone of inhibition) against Staphylococcus aureus and Candida albicans among the tested bacteria and fungi, respectively. For the first time, we are reporting here the bioactivity of a red fluorescent protein purified from the silkworm excreta against clinically important bacteria and fungi. The bioactive SE-RFP has two absorption peaks at 280 and 603 nm and, it has exhibited fluorescence emission peaks at 334 and 619 nm upon exciting at 280 and 603 nm, respectively. The SE-RFP being an aqua-soluble, economically feasible and eco-friendly protein, it can therefore be used for the practical applications as an effective antimicrobial agent.
Insights
Silkworm excretory red fluorescent protein (SE-RFP) shows strong antimicrobial activity against various bacteria and fungi. This eco-friendly protein is a promising candidate for developing new antimicrobial agents.
Area of Science:
- Biochemistry
- Microbiology
- Biotechnology
Background:
- Silkworm excretory red fluorescent protein (SE-RFP) is a novel protein with potential biological activities.
- Antimicrobial resistance necessitates the discovery of new therapeutic agents.
Purpose of the Study:
- To investigate the antimicrobial properties of purified SE-RFP.
- To evaluate its efficacy against clinically relevant bacterial and fungal strains.
Main Methods:
- Antimicrobial assays using the agar cup plate method.
- Determination of minimum inhibitory concentration (MIC) via agar dilution technique.
- Spectroscopic analysis of SE-RFP's absorption and emission properties.
Main Results:
- SE-RFP demonstrated broad-spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria and fungi.
- Highest activity was observed against Staphylococcus aureus and Candida albicans.
- SE-RFP exhibits characteristic absorption and fluorescence emission peaks.
Conclusions:
- Purified SE-RFP possesses significant antimicrobial potential.
- Its water solubility, economic feasibility, and eco-friendly nature make it suitable for practical antimicrobial applications.
- This study reports for the first time the bioactivity of silkworm excreta-derived fluorescent protein.
