7WKF

Antimicrobial peptide-LaIT2

Summary for 7WKF

• Entry DOI: 10.2210/pdb7wkf/pdb
• NMR Information: BMRB: 36469
• Descriptor: Beta-KTx-like peptide LaIT2 (1 entity in total)
• Functional Keywords: cyana 2.1 scorpion antimicrobial peptide, structural protein
• Biological source: Liocheles australasiae
• Total number of polymer chains: 1
• Total formula weight: 6650.89

Authors

Tamura, M.,Morita, H.,Ohki, S. (deposition date: 2022-01-09, release date: 2023-04-05, Last modification date: 2024-11-13)

Primary citation

Tamura, M.,Tatsushiro, C.,Morita, E.H.,Ohki, S.
Structural and functional studies of LaIT2, an antimicrobial and insecticidal peptide from Liocheles australasiae.
Toxicon, 214:8-17, 2022

PubMed Abstract: LaIT2, composed of 59 amino acid residues, is a peptide toxin isolated from the venom of the Yaeyama scorpion, Liocheles australasiae. LaIT2 is toxic to insects but not most mammals. The N- and C-domains of LaIT2 are known to possess antimicrobial and insecticidal activities, respectively. However, the molecular mechanisms are largely unknown because of the lack of a three-dimensional structure of LaIT2. Thus, we elucidated the solution NMR structure of LaIT2. LaIT2 adopts a β-KTx-like two-domain structure, in which the N- and C-terminal domains form a random coil and an α-β-β motif, respectively. Trifluoro ethanol and liposomes titration experiments showed that the unstructured N-domain of LaIT2 has the ability to form an α-helix. The N-terminal helix is amphiphilic, and one side of the helix is positively charged. Measurements of the antimicrobial and insecticidal activities of LaIT2 mutants suggested K15 in the N-domain was found to be responsible for the antimicrobial activities, whereas L53 and L54 in the C-domain were key residues involved in the insecticidal activity. Moreover, K21 in the N-domain is important for both activities. Therefore, two domains are suggested that they work together to show antimicrobial and insecticidal activity.

PubMed: 35490851
DOI: 10.1016/j.toxicon.2022.04.015

Experimental method

SOLUTION NMR