The aim of this study was to investigate the prokaryotic expression of antimicrobial peptide cathelicidin （CATH） PR1 and PR2 from the skin of Paa robertingeri in Escherichia coli. Two active peptides, CATH PR1 and C...The aim of this study was to investigate the prokaryotic expression of antimicrobial peptide cathelicidin （CATH） PR1 and PR2 from the skin of Paa robertingeri in Escherichia coli. Two active peptides, CATH PR1 and CATH PR2, belong to the CATH family in the skin of P. robertingeri. CATH PR1 has a relatively high antimicrobial activity, especially for the drug-resistant strains found in clinical practice; however, no antimicrobial activity has been found in CATH PR2. The molecular weights of both CATH PR1 and CATH PR2 are relatively low （3195.88 and 2838.34 Da, respectively）. Thus, the genetic processes, as well as the expression and purification of these proteins, are difficult to perform. Therefore, in this study, CATH PR1 and CATH PR2 genes were tandem ligated and then connected to the plasmid pET-32a. This reconstructed plasmid was then transfected into the expression vector E. coli BL21 to construct the recombinant expression system. The fusion expression of peptide PR was stable in E. coli after induction with 1.0 mol/L isopropyl β-D-1-thiogalactopyranoside at 37℃ for 4 h. The antimicrobial activity assay using Staphylococcus aureus （Song） and Candida albicans 08030102 showed that the antimicrobial activity of PR was similar to the antimicrobial activity of CATH PR1. This study showed that artificial modification of the amino acid sequences of PR1 and PR2 could result in better protein expression in prokaryotes, and the fusion protein expressed had relatively high antimicrobial and other biological activities. In conclusion, the findings suggest future prospects of the commercialization of this method.展开更多
The objectives of this study are to present a detailed and comprehensive description of the osteology of Quasipaa robertingeri （Anura： Dicroglossidae）, to provide osteological evidence for taxonomy, and to explore ...The objectives of this study are to present a detailed and comprehensive description of the osteology of Quasipaa robertingeri （Anura： Dicroglossidae）, to provide osteological evidence for taxonomy, and to explore the adaptive traits of Q. robertingeri. We comprehensively studied the osteology of 2 adult specimens （1 male 98A00351 and 1 female 98A0041） of Q. robertingeri using conventional methods. Our osteological examination of Q. robertingeri shows that 1） the nasals are large and connect with one another medially; 2） the sphenethmoid is completely covered by the nasals and the frontopatietals, and thus it is not exposed dorsally; 3） the vomerine teeth are well-developed; 4） the anterior parts of the diapophyses＇ of the presacral II protrude forward in the male, the same observation was made in the presacrals II and III in the female; 5） the pectoral girdle is firmisternal; 6） the omosternum is fan-shaped posteriorly, and almost equal to the length of the mesosternum; 7） the xiphistemum is W-shaped with a deep incision posteriorly; 8） the humerus of the male is more developed in the crista ventralis, the crista medialis, and the crista lateralis; 9） the metacarpal II of the male presents with a nuptial tuber; and 10） the distal phalanges of the digits are anchorshaped. Ultimately, the unique characteristics listed are most likely adaptations to the environment and amplexus of Q. robertingeri.展开更多
基金supported by the Industry-University-Research Project of Application of the Active Substances from Amphibian Skin from the Education Ministry of Guizhou (Q. J. HE and K. Y. ZHI [2013]121)
文摘The aim of this study was to investigate the prokaryotic expression of antimicrobial peptide cathelicidin （CATH） PR1 and PR2 from the skin of Paa robertingeri in Escherichia coli. Two active peptides, CATH PR1 and CATH PR2, belong to the CATH family in the skin of P. robertingeri. CATH PR1 has a relatively high antimicrobial activity, especially for the drug-resistant strains found in clinical practice; however, no antimicrobial activity has been found in CATH PR2. The molecular weights of both CATH PR1 and CATH PR2 are relatively low （3195.88 and 2838.34 Da, respectively）. Thus, the genetic processes, as well as the expression and purification of these proteins, are difficult to perform. Therefore, in this study, CATH PR1 and CATH PR2 genes were tandem ligated and then connected to the plasmid pET-32a. This reconstructed plasmid was then transfected into the expression vector E. coli BL21 to construct the recombinant expression system. The fusion expression of peptide PR was stable in E. coli after induction with 1.0 mol/L isopropyl β-D-1-thiogalactopyranoside at 37℃ for 4 h. The antimicrobial activity assay using Staphylococcus aureus （Song） and Candida albicans 08030102 showed that the antimicrobial activity of PR was similar to the antimicrobial activity of CATH PR1. This study showed that artificial modification of the amino acid sequences of PR1 and PR2 could result in better protein expression in prokaryotes, and the fusion protein expressed had relatively high antimicrobial and other biological activities. In conclusion, the findings suggest future prospects of the commercialization of this method.
基金provided by the National Natural Science Foundation of China (NSFC) to Xiaohong CHEN (Grant Nos.30870277,31372164,31572245)the key discipline of ecology of Henan Province, and the innovation team of science and technology of Henan Province (C20140032)
文摘The objectives of this study are to present a detailed and comprehensive description of the osteology of Quasipaa robertingeri （Anura： Dicroglossidae）, to provide osteological evidence for taxonomy, and to explore the adaptive traits of Q. robertingeri. We comprehensively studied the osteology of 2 adult specimens （1 male 98A00351 and 1 female 98A0041） of Q. robertingeri using conventional methods. Our osteological examination of Q. robertingeri shows that 1） the nasals are large and connect with one another medially; 2） the sphenethmoid is completely covered by the nasals and the frontopatietals, and thus it is not exposed dorsally; 3） the vomerine teeth are well-developed; 4） the anterior parts of the diapophyses＇ of the presacral II protrude forward in the male, the same observation was made in the presacrals II and III in the female; 5） the pectoral girdle is firmisternal; 6） the omosternum is fan-shaped posteriorly, and almost equal to the length of the mesosternum; 7） the xiphistemum is W-shaped with a deep incision posteriorly; 8） the humerus of the male is more developed in the crista ventralis, the crista medialis, and the crista lateralis; 9） the metacarpal II of the male presents with a nuptial tuber; and 10） the distal phalanges of the digits are anchorshaped. Ultimately, the unique characteristics listed are most likely adaptations to the environment and amplexus of Q. robertingeri.
