Preparation Of A New Antibacterial Peptide And Studies Of Pharmacological, Pharmacodynamic And Toxicological Test

ObjectiveTo express antibacterial peptide ABPj-1 in Pichia pastoris and detect its antibacterial and antiviral activities.To study the influence of ABP-j1 on the nervous system, respiratory system and cardiovascular system of laboratory animals. And understand the effect of ABP-j 1 toxicity, and mutagenicity. offer an experimental basis for clinical application.MethodThe gene sequence of ABPj-1 was synthesized and cloned into expression vector pPIC9K. The recombinant plasmid pPIC9K-ABPj-1 was transformed into Pichia pastoris GS115, positive clones were selected with G418 and induced to express objective peptide. The expressed peptide was identified, then tested for thermostability, its antibacterial and antiviral activities. By observing the influence of ABPj-1, which was given by intragastric administration to mice, on the independent activity, understand the impact on nervous system of laboratory animal. By observing many physiological indices such as respiratory rate, breathing range, blood pressure, heart rate, etc in anaesthetized dogs, understand the impact on the respiratory system and cardiovascular system of laboratory animal. Acute toxicity test, long-term toxicity test, micronucleus test and sperm abnormail test were carried out to study on effect of toxicity.ResultsThe recombinant plasmid pPICK9K-ABPj-1 has been successfully constructed and expressed stably in Pichia pastoris. A molecular weight of about 4.0 KD protein band appeared on SDS-PAGE gel. It showed good thermostability, effective antibacterial and antiviral activities.In this experiment, ABPj-1 did not obviously influence general behavior and independent activity in mice. It also had no influence on respiratory rate, breathing range, blood pressure and heart rate in the anesthetized dogs. So ABPj-1 has not obvious influence on the nervous system, respiratory sytem and cardiovascular system of laboratory animals.In the acute toxicity test, all laboratory animals were alive, so LD50 was not accouted. And in the long-term toxicity, micronucleus test and sperm abnormal test, it did not obviously influence, so it can be used.