Novel antibacterial peptides from the skin secretion of the Indian bicoloured frog Clinotarsus curtipes

Abstract

HPLC elution profile and MALDI TOF MS analysis of electro-stimulated skin secretion of the Indian Ranid frog Clinotarsus curtipes of the Western Ghats confirmed the presence of multiple peptides. Peptides eluted out of the C18 column at higher hydrophobic solvent region showed antibacterial activity against diverse bacterial strains, including the clinical isolates of V. cholerae and methicillin resistant Staphylococcus aureus (MRSA). Peptidomic analysis of the most potent chromatographic effluent fraction identified five novel peptide amides having sequence homology with brevinin family. These peptides are named as brevinin1CTcu1 (B1CTcu1) to brevinin1CTcu5 (B1CTcu5). Peptide B1CTcu1 is non-haemolytic while the others are haemolytic in nature but all elicited potential antibacterial activity. B1CTcu5 is a twenty-one residue peptide amide having proline hinge region in the middle and the typical C-terminal intramolecular disulfide-bridged hepta peptide domain (Rana box) that is present in most of the brevinin peptides. Analysis of their killing kinetics with E. coli and S. aureus and the ability to induce membrane depolarization proved that these are two independent events. These novel multifunctional peptides play an important role to protect C. curtipes from invading pathogenic microorganisms present in the environment.

Biochemical Profile, Biological Activities, and Toxic Effects of Proteins in the Rhinella schneideri Parotoid Gland Secretion

“…Most of the studies dealing with toad parotoid gland and skin secretions focus on the biological activities of biogenic amines, alkaloids, and peptides. Therefore, these molecules and their pharmacological and toxic effects are well characterized (Abraham et al., ). However, there is limited information regarding the content and identification of proteins from toad parotoid glands, as well as their pharmacological and toxic properties.…”

“…Although parotoid secretions are commonly reported as sources of toxic compounds, some studies have reported the presence of molecules having pharmacological activities. The action against cardiovascular disorders, cancer, microbial infections, diabetes, and inflammation are examples of activities related to biogenic amines, cardiotonic steroids, and alkaloids (Meng et al., ; Abraham et al., ). However, information on purification, biochemical characterization, and biological activities of proteins and peptides from these glands is very limited in the literature.…”

Antibacterial Activity of Skin Secretion of Bleeding Toad <i>Leptophryne cruentata</i> and Javan Tree Frog <i>Rhacophorus margaritifer</i>

“…subtilis, E. coli, Proteus vulgaris, Sarcina lutea, Enterobacter aerogenes, Salmonella typhimurium and S. aureus. Similarly, Abraham et al (2014) found that electrically stimulated skin secretion of the Indian Ranid frog Clinotarsus curtipes of the Western Ghats, Kerala, India contains multiple peptides having antibacterial activity against diverse bacterial strains, including V. cholerae and Methicillin Resistant S. Aureus (MRSA). Dorsal skin secretions of Iranian frog, Rana ridibanda, was also shown to have a significant antibacterial activity against MRSA (Abbasi et al, 2007).…”

Comparative efficacy analysis of anti-microbial peptides, LL-37 and indolicidin upon conjugation with CNT, in human monocytes

“…2a, e). The immune modulatory properties of AMPs include modulating pro- and anti-inflammatory responses through [41] various signaling pathways [40] directly [42] or indirectly [43] recruiting effector cells including phagocytes to the site of infection, enhancing intracellular [44] and extracellular [45] bactericidal activity. AMPs also mediate macrophage differentiation [46] which is required for effective clearance of pathogens from the host.…”