Isolation and characterisation of antimicrobial peptides from deer neutrophils.

The New Zealand deer industry is the largest and most advanced in the world. Antimicrobial peptides have been isolated from a wide range of organisms, but as yet there have been no reports on any from deer. This work investigates the antimicrobial activity and characterisation of peptides isolated from Cervus elaphus blood. It was found that deer blood contains proline/arginine-rich cathelicidins, similar to Bac5 peptides isolated from cattle, sheep and goats. A beta-defensin was also isolated that had a conserved amino acid sequence and mass similar to bovine neutrophil beta-defensins. The cathelicidin displayed strong activity against Gram-negative bacteria, but lesser activity against Gram-positive bacteria and yeast, whilst the beta-defensin showed good activity against all three test organisms.