Synthesis and structure-function study about tenecin 1, an antibacterial protein from larvae of Tenebrio molitor.
Tenecin 1, an inducible antibacterial protein secreted in the larvae of Tenebrio molitor, has a long N-terminal loop and common structural feature of insect defensin family corresponding to cysteine stabilized alpha/beta motif. To study the function of the N-terminal loop and disulfide bridges, N-terminal loop deleted tenecin 1, reduced tenecin 1 and tenecin 1 were chemically synthesized and their activities were measured. N-terminal loop deleted tenecin and reduced tenecin 1 did not show antibacterial activity. Circular dichroism (CD) spectroscopy data revealed that the alpha-helical content of tenecin 1 and the other proteins increased in the presence of 50% (v/v) trifluoroethanol (TFE) and the alpha-helical content of tenecin 1 was much higher than that of the other proteins in buffer with or without 50% (v/v) TFE. These results suggest that disulfide bridges are necessary for the activity structure and the N-terminal loop plays an important role in the increase of alpha-helix in the membrane mimetic environment and the activity.
Lee
K H
KH
Protein Chemistry Laboratory, Mogam Biotechnology Research Institute, Yongin-City, South Korea. lkh@kgcc.co.kr
Hong
S Y
SY
Oh
J E
JE
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002942:Circular Dichroism; D004220:Disulfides / Q000737:chemistry; D006094:Gram-Positive Bacteria / Q000187:drug effects; D019476:Insect Proteins / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D007814:Larva / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017510:Protein Folding; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D013712:Tenebrio / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D004220:Disulfides; D019476:Insect Proteins; C091169:tenecin 1 protein, Tenebrio molitor