Research Article Cationic Bioactive Peptide from the Seeds of Benincasa hispida Sunayana Sharma, 1 Hirday Narain Verma, 1 and Nilesh Kumar Sharma 1,2 1 School of Life Sciences, Jaipur National University, Jaipur 302025, India 2 Department of Molecular Biology and Genetics, Dr. D.Y. Patil Vidyapeeth, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Mumbai-Bangalore Highway, Tathawade, Pune 411033, India Correspondence should be addressed to Nilesh Kumar Sharma; nilesh.sharma@dpu.edu.in Received 18 October 2013; Revised 3 March 2014; Accepted 4 March 2014; Published 16 April 2014 Academic Editor: Tzi Bun Ng Copyright © 2014 Sunayana Sharma et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A designated bioactive peptide “Hispidalin” puriied from the seeds of Benincasa hispida, which is a medicinal plant, belongs to Cucurbitaceae family. Puriication was achieved by using a procedure consisting of extraction from potassium phosphate bufer followed by FPLC and HPLC steps. Based on amino acid residue, this peptide is amphipathic and basic with one net positive charge having isoelectric pH 8.1. his peptide is without sulphur containing amino acid suggesting its extended conformation lacking double bond secondary structure. he results obtained from MALDI-TOF suggested that Hispidalin is of molecular mass 5.7 KDa with 49 amino acid residues and conirmed SDS-PAGE resolved ∼6.0 KDa protein band. his novel and unknown peptide “Hispidalin” showed broad and potent inhibitory efects against various human bacterial and fungal pathogens; its growth inhibition was signiicantly comparable with commercial antibacterial and antifungal drugs. he Hispidalin at 40 g/mL concentration exhibited 70.8% DPPH free radical-scavenging activity and 69.5% lipid peroxide inhibition. hus, in the present study, Hispidalin demonstrated remarkable antimicrobial and antioxidant potentials from the seeds of B. hispida. 1. Introduction Plants are one of the major sources of peptide. Potentially, peptides have considerable medical importance since they [1] afect the stability and sensory quality of plant foods [2]. Research on bioactive proteins/peptide has been increasing including work on the development of pathogen resistant and antimicrobial compounds [2–6]. In recent years, extensive scientiic evidence has been provided for the existence of biological active peptides and proteins derived from plants that might have beneicial efects upon human health [6–12]. Peptides have certain biological activities like antimicrobial and antioxidant activities [2, 4, 6, 13]. Several plants in the family Cucurbitaceae have been widely used as medicine in many countries of Asia including India. B. hispida commonly known as wax guard has been used in treatment of gastrointestinal problems [14], antidepressant-like activity [15], antinociceptive, antipyretic [16], anticompulsive efects [17], and antimicrobial activity [18]. Plants are rich in a wide variety of protein that has found antimicrobial properties [1, 2, 6, 11, 19]. Plants do not have an immune system directly comparable with that of animals. hus, to protect themselves from infection by a variety of pathogens, plants have evolved a host of defense mechanisms [2, 4, 12, 19]. In recent decades, a number of antimicrobial peptides (AMPs) have been identiied or predicted from various organisms including plant sources. AMPs in general consist of 10–50 amino acid residues [2, 13, 19]. hese peptides do not have any speciic consensus amino acid sequences that are responsible for their biological activity, but most of them maintain certain common features, such as containing positive charge and relatively hydrophobic and amphipathic structure. Antimicrobial proteins are produced by many organisms including vertebrates, invertebrates, plants, and fungi [5, 12, 20, 21]. hey serve to protect the organisms from pathogenic bacteria and fungus, which would bring devastating damage. Several plant proteins capable of inhibiting the growth of agronomically important pathogens have been isolated during the last few years [4, 8, 20]. Cationic peptides vary considerably in sequence and structure, with a few common features. Cationic peptides are amphipathic meaning they possess both a hydrophobic region that interacts with lipids Hindawi Publishing Corporation International Journal of Peptides Volume 2014, Article ID 156060, 12 pages http://dx.doi.org/10.1155/2014/156060