Discovery of a new antiviral protein isolated Lonomia obliqua analysed by bioinformatics and real-time approaches

Abstract

This study presents a new recombinant protein that acts as a powerful antiviral (rAVLO-recombinant Antiviral protein of Lonomia obliqua). It was able to reduce the replication by 10(6) fold for herpes virus and by 10(4) fold for rubella virus. RT-PCR of viral RNA rAVLO treated infected cells also showed similar rate of inhibition in replication. The analysis of this protein by bioinformatics suggests that this protein is globular, secreted with a signal peptide and has the ability to bind to MHC class I. It was found that there are several protein binding sites with various HLA and a prevalence of α-helices in the N-terminal region (overall classified as a α/β protein type). BLAST similarity sequence search for corresponding cDNA did not reveal a similar sequence in Genbank, suggesting that it is from a novel protein family. In this study we have observed that this recombinant protein and hemolymph has a potent antiviral action. This protein was produced in a baculovirus/Sf-9 system. Therefore, these analyses suggest that this novel polypeptide is a candidate as a broad spectrum antiviral.

Keywords: Antiviral; Bioinformatics; Lonomia obliqua.

Fig. 1

Rubella virus transcription levels in cells treated with rAVLO clones and total hemolymph measured by real time PCR. Different virus concentrations were used (each bar)

Fig. 2

Herpes transcription levels in cells treated with rAVLO clones and total hemolymph measured by real time PCR. Cells were treated with rAVLO clones and total hemolymph

Fig. 3

Second structure and posttranslational modifications sites predictions diagram in protein sequence. Each bar colored represents a second structure type and spaces represents coil/unstructured regions. Colored lines represents different sites predicted by Prosite. (Color figure online)

Fig. 4

Hydrophylic/polar prediction along the protein using Gratham and Zimmerman calculation methodologies. Higher values in both methods indicates higher hydrophylic/polar regions

Fig. 5

Hydrophobic prediction along the protein using different methods. Higher values indicate higher hydrophobic regions in Miyasawa, OMH Sweet, Rao and Argos, Rose, Roseman and Tanford methods; the opposite occurs in Bull and Breese, Guy and Hopp and Wodds predictions. X-axis residue position, Y-axis score calculated

Fig. 6

Protscale predictions for mutability, antigenicity and accessibility of each residue in the protein sequence

Fig. 7

Epitope prediction results using NetCLT results. The number indicates the first amino acid position of the epitope. Each color represents one MHC allele which binds to the region. Multicolor bars indicate epitopes recognized by more than one allele. (Color figure online)