Production of antimicrobial peptide (Oxysterlin 1) in Escherichia coli with ELP self-cleavage tag / 生物工程学报

Antimicrobial peptides are the most promising alternatives to antibiotics. However, the strategy of producing antimicrobial peptides by recombinant technology is complicated and expensive, which is not conducive to the large-scale production. Oxysterlin 1 is a novel type of cecropin antimicrobial peptide mainly targeting on Gram-negative bacteria and is of low cytotoxicity. In this study, a simple and cost-effective method was developed to produce Oxysterlin 1 in Escherichia coli. The Oxysterlin 1 gene was cloned into a plasmid containing elastin-like polypeptide (ELP) and protein splicing elements (intein) to construct the recombinant expression plasmid (pET-ELP-I-Oxysterlin 1). The recombinant protein was mainly expressed in soluble form in E. coli, and then the target peptide can be purified with a simple salting out method followed by pH changing. The final yield of Oxysterlin 1 was about 1.2 mg/L, and the subsequent antimicrobial experiment showed the expected antimicrobial activity. This study holds promise for large-scale production of antimicrobial peptides and the in-depth study of its antimicrobial mechanism.

Relationship Between Angiotensin Converting Enzyme Gene Polymorphism,Angiotensin Converting Enzyme Activity And Coronary Heart Disease / 中国医师杂志

Objective The relationship among angiotensin converting enzyme(ACE) gene polymorphism,angiotensin converting enzyme activity and coronary heart disease(CHD) was studied.Method Teh polymerase chain reaction was used to detect an insertion/deletion(I/D) of ACE gene polymorphism in the sixteen intron,then genotype and allele freqencies were counted .The method of enzyme coupling ratio was used to detect ACE activity .Results In 51 case with CHD ,the DD genotype and D allele freqencies of ACE gene were 35% and 61% respectively ,ACE average activity was (350 3?91 1)su/L.In 83 normal control subject,they were 16% and 45% and (286 7?79 6)su/L respectively.The freqencies of DD genotype and D allele and ACE average activity had significant difference.Conclusion The deletion polymorphism of ACE gene might be an latent risk factor.The higher ACE activity might play an important role in the development of CHD.

Correlation Between Apolipoprotein E Gene Polymorphism and Alzheimer and Coronary Heart Disease / 中国医师杂志

Objective Apolipoprotein E(ApoE) gene polymorphism and alzheimer and coronary heart disease was studied ,and the correlation between them was evaluated.Methods The polymerase chain reaction-restriction fragment length polymorphism was used to amply 227 base-pari DNA fragment in the fourth exon of ApoE gene,and digested them with restriction enzyme CfoI,electrophoresis on 8% polyacrylamaid gel for the cleavaged products,subsequently genotype was determined by silver staining and allele frequencies were counted.Results apoE genotype and allele frequencies was detected in 33 case with Alzheimer and 37 case with coronary heart disease.The results showed that the frequencies of ApoE ? 4 was significantly higher than that in age-matched controls(P

Relationship between Angiotensin Converting Enzyme Gene Polymorphism and Serum Angiotensin Converting Enzyme Activity / 中国医师杂志

To study the relationship between angiotensin converting enzyme(ACE) gene polymorphism and angiotensin converting enzyme activity,the polymerase chain reaction(PCR) was used to detect an insertion/deletion(I/D) polymorphism of ACE gene in its sixteenth intron.The genotype,enzyme coupling spectrophotometry were used to measure serum ACE activity among the three genotypes.Results showed that the Serum ACE activities were (337 6?92 0),(292 7?76 5 )and(243 5?58 9)u/L for genotypes DD,ID and ⅠⅠ respectively.The findings indicate that the ACE gene polymorphism closely associated with serum ACE activity.