Novel antimicrobial peptide isolated from penaeus monodon

Abstract

The present invention provides an antimicrobial peptide, monodoncin, which is isolated and purified from Penaeus monodon and is capable of being mass produced by molecular cloning techniques in a heterologous expression system, such as yeast. Monodoncin demonstrates a wide-range of bacteriostatic and bactericidal effects on G(−) and G(+) bacteria as well as fungicidal activities, and can be used in combination with conventional antibiotics as “cocktail therapy” to improve the therapeutic effects of the conventional antibiotics.

We claim:  
     
         1 . An antimicrobial peptide having an amino acid sequence of SEQ ID NO: 1 or a fragment thereof.  
     
     
         2 . The antimicrobial peptide of  claim 1 , wherein said antimicrobial peptide is isolated and purified from tiger shrimp ( Penaeus monodon ).  
     
     
         3 . The antimicrobial peptide of  claim 2 , wherein said antimicrobial peptide is isolated and purified from hemocytes of tiger shrimp.  
     
     
         4 . The antimicrobial peptide of  claim 1 , wherein said fragment of said antimicrobial peptide contains residue 20-glutamine to residue 74-glycine of said amino acid sequence.  
     
     
         5 . A polynucleotide comprising a nucleic acid sequence of SEQ ID NO:2 or a fragment thereof, which encodes said antimicrobial peptide of  claim 1 .  
     
     
         6 . The polynucleotide of  claim 5 , wherein said fragment of said nucleic acid sequence is SEQ ID NO:3.  
     
     
         7 . The polynucleotide of  claim 5 , wherein said fragment of said nucleic acid sequence is SEQ ID NO: 4.  
     
     
         8 . A recombinant construct comprises a nucleic acid sequence according to  claim 7  and a vector.  
     
     
         9 . The recombinant construct according to  claim 8 , wherein said vector is a plasmid or a viral carrier.  
     
     
         10 . The recombinant construct according to  claim 8 , wherein said recombinant construct is expressed in a host.  
     
     
         11 . The recombinant construct according to  claim 10 , wherein said host is yeast.  
     
     
         12 . A composition comprising the antimicrobial peptide of  claim 1  and a carrier.  
     
     
         13 . The composition according to  claim 12 , wherein said composition is capable of treating a host with bacterial and/or fungal infection.  
     
     
         14 . The composition according to  claim 13 , wherein said host is an aquatic species.  
     
     
         15 . The composition according to  claim 14 , wherein said aquatic species is finfish, crustacean, or molluscus.  
     
     
         16 . The composition according to  claim 13 , wherein said host is an animal.  
     
     
         17 . The composition according to  claim 16 , wherein said animal is chicken or swine.  
     
     
         18 . The composition according to  claim 13 , wherein said host is a human.  
     
     
         19 . A pharmaceutical composition comprising said antimicrobial peptide of  claim 1  and a pharmaceutically acceptable carrier.  
     
     
         20 . The pharmaceutical composition according to  claim 19 , wherein said pharmaceutical composition is orally administered or parenterally injected into a human.  
     
     
         21 . The pharmaceutical composition according to  claim 19 , wherein said pharmaceutical composition is a topical preparation for external use.  
     
     
         22 . A composition for cocktail therapy comprising the antimicrobial peptide of  claim 1  and at least an antibiotic.  
     
     
         23 . The composition according to  claim 12 , wherein said antibiotic is at least one selected from the group consisting of acyclovir, cecropin A, cecropin B, magainin II, pleurocidin, cefaclor, cefadroxil, ciprofloxacin, erythromycin, penicillin, amoxcilin, and tetracycline.  
     
     
         24 . A method for inhibiting growth of a microorganism in a host comprising administrating said composition according to  claim 12  to said host.  
     
     
         25 . The method according to  claim 24 , wherein said composition is administered orally or parenterally injected into said host.  
     
     
         26 . The method according to  claim 24 , wherein said composition is topically administered into said host.  
     
     
         27 . The method according to  claim 24 , wherein said microorganism is a bacteria or a fungus.  
     
     
         28 . A method for killing a microorganism in a host comprising: 
 administrating said composition according to  claim 12  to said host.    
     
     
         29 . A method for improving the effectiveness and efficacy of an antibiotic in a patient comprising co-adminstering said pharmaceutical composition of  claim 19  with said antibiotic.  
     
     
         30 . A transgenic crustacean whose somatic and germ cells contain at least one genomically integrated copy of said recombinant construct of  claim 7 , 
 wherein said nucleic acid sequence expresses an antimicrobial peptide both spatially and temporally during development of said crustacean.    
     
     
         31 . The transgenic animal of  claim 30 , wherein said crustacean is  Penaeus vannamei.