Purification, Identification, CDNA Cloning, And Activity Analysis Of Novel Antimicrobial Peptides From Skin Of Amolops Ricketti

As one of the large amphibian groups, there are a total of45species of Amolops in theworld. However, the antimicrobial peptides existing in this genus has not been extensivelystudied. As one of the large amphibian groups, there are a total of45species of Amolops thatare known to distribute mainly from western and southern Asia. However, only a few ofAMPs have been characterized previously. In this study, cDNAs encoding five novelantimicrobial peptide (AMP) precursors were cloned by screening the skin-derived cDNAlibrary of Amolops ricketti, a frog species that exists in southern and western parts of China.Protein sequence analysis led to the identification of five deduced peptides, three belonging tothe brevinin-1family and two belonging to the brevinin-2family of amphibian AMPs. Thus,they were named as brevinin-1RTa (FLPLLAGVVANFLPQIICKIARKC), brevinin-1RTb(FLGSLLGLVGKVVPTLFCKISKKC),brevinin-1RTc (FLGSLLGLVGKIVPTLICKISKKC),brevinin-2RTa (GLMSTLKDFGKTAAKEIAQSLLSTASCKLAKTC) and brevinin-2RTb(GILDTLKEFGKTAAKGIAQSLLSTASCKLAKTC), respectively. The actual presence andcharacterization of brevinin-1RTa, brevinin-1RTb, brevinin-2RTa and brevinin-2RTb wasconfirmed by RP-HPLC and LC-MS/MS-based proteomics approach. All of the peptidesdisplayed different antimicrobial potency against a variety of microorganisms. In addition,brevinin-2RTa and brevinin-2RTb were found to have relatively low hemolytic activityagainst mammalian red blood cells in vitro, which could potentially be used for developingnovel anti-infection agents.