1H, 13C and 15N resonance assignments and secondary structures of cyclophilin 2 from Trichomonas vaginalis

Abstract

Cyclophilins are peptidyl prolyl isomerases that play an important role in a wide variety of biological functions like protein folding and trafficking, intracellular and extracellular signaling pathways, nuclear translocation and in pre-mRNA splicing. Two cyclophilins have been identified in the parasitic organism Trichomonas vaginalis and were named as TvCyP1 and TvCyP2. The 2 enzymes have been found to interact with Myb transcription factors in the parasite which regulate the iron induced expression of ap65-1 gene leading to cytoadherence of the parasite to human vaginal epithelial cells to cause the disease trichomoniasis. TvCyP2 was found to interact specifically with Myb3 to regulate nuclear translocation of the transcription factor. It would be intriguing to identify the binding site of both proteins as it could pave way to newer targets for drug discovery. Here we report the H,C and N resonance assignments and secondary structure information of TvCyP2 that could help us investigate the interaction between Myb3 and TvCyP2 in detail using NMR.

N-Terminal Segment of TvCyP2 Cyclophilin from Trichomonas vaginalis Is Involved in Self-Association, Membrane Interaction, and Subcellular Localization

“…Unfortunately, this peptide is too hydrophobic to be dissolved in the aqueous buffer, so another 16-residue peptide, TvCyP23-18, was synthesized and used for NMR study because it is highly soluble and gives good NMR data. Comparison of 2D 1 H- 15 N HSQC spectra for 15 N-labelled TvCyP2 without and with TvCyP23-18 (molar ratio 1:5) showed that active-site residues Q83, A121, N122, and W141 and S2 pocket residues S101, S123 and S130 have significant We previously published the secondary structure of TvCyP2 in solution based on the chemical shift index [48], which is mostly in good agreement with the X-ray structure. From the X-ray structure, we could well explain the effect causing the unusual chemical shift on some specific residues.…”

“…Biomolecules 2020, 10, x FOR PEER REVIEW 10 of 22 cyclophilin, this finding let us assume that the N-terminal segment behaves as a substrate like CsA in the hCyPA-CsA complex. We previously published the secondary structure of TvCyP2 in solution based on the chemical shift index [48], which is mostly in good agreement with the X-ray structure. From the X-ray structure, we could well explain the effect causing the unusual chemical shift on some specific residues.…”

“…We previously published the secondary structure of Tv CyP2 in solution based on the chemical shift index [ 48 ], which is mostly in good agreement with the X-ray structure. From the X-ray structure, we could well explain the effect causing the unusual chemical shift on some specific residues.…”

“…All NMR spectra were acquired on Bruker AVANCE 600 and 800 MHz spectrometers equipped with a z-gradient TXI cryogenic probes (Bruker, Karlsruhe, Germany). Because we already published the backbone resonance assignment of TvCyP2 by using 3D triple resonance experiments [48], we only performed 2D NMR experiments in this study, as described below. 2D 1 H- 15 N HSQC titration experiments on both 15 N-TvCyP2 and 15 N-TvCyP2-∆N with TvCyP2 3-18 peptide were acquired at 800 MHz and 310 K. 2D 1 H-TOCSY, 1 H-COSY, and 1 H-NOESY on the Myb3 52-59 peptide were acquired at 600 MHz and 283 K to determine its proton resonance assignments.…”