DETERMINATION OF PRIMARY STRUCTURE AND ITS BACTERICIDAL ACTIVITY OF NEW CB ISOLATED FROM Crotalus durissus collilineatus

Oliveira, D.G.(1), Toyama, M.H.(1), Carneiro, E.M.(2), Boschero, A.C.(2), Joazeiro, P.P.(3), Beriam, L.O.S.(4), Marangoni, S.(1)

(1)Departamento de Bioquímica, (2)Departamento de Fisiologia e Biofísica, (3)Departamento de Histologia e Embriologia Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, Brasil. (4)Laboratório de Bacteriologia Vegetal, Centro Experimental do Instituto Biológico de Campinas, São Paulo, S.P, Brasil.

Objectives: In this work we determined the amino acid sequence of new crotalic PLA₂ from the C. d. collilineatus venom and its antibacterial activities on Xanthomonas axonopodispv. passiflorae and C. m. sp michiganesnis.

Methods and Results: The amino acid sequence of novel PLA₂ was determined in the procise f (Applied Biosystem) and its amino acid sequence was: HLLQFNKMIKFETRRNAIPFYAFYGCYCGWGGRPKDATDRDRCCFVHDCCYEKLTGCNYKWDFYRYSLRSGYFQCGKGTWCEQQICECDRVAAECLRRSLSTYRYGYMIYPKSRCRKPSETC. Cdcolli F6 shows higher antibacterial effect on the Gram-positive than Gram-negative bacterial strains. Thus, the inhibition ofgrowth was of 95% and 85% for Claribacter ssp(Gran positive) and for Xanthomonas ssp, (Gran negative), respectively.  CdcolliF6 to produce cell membrane disruption allowing the penetration of the toxin into the cells (Xanthomonas ssp), and also induced several modifications principally in the LPS composition as suggested by electrophoresis analysis.

Conclusion: In conclusion, the bactericidal efficacy of PLA₂(s), in general, and of Cdcolli F6, in particular, is dependent on both the presence of positive amino acid residue that allows electrostatic interaction between the Cdcolli F6 molecule and the bacterial membrane and their catalytic activity that hydrolysis the bacterial cell membrane.

CORRESPONDENCE TO:

Daniela Garcia de Oliveira, Rua Antônio José Silva Martelinho, 470 Apto. 12, Campinas, SP, CEP: 13031-580, Brasil, Email: gaveira@yahoo.com.br