Ribonucleases are promising proteins to be used in anticancer therapy but their lifetime in bloodstream or stability are issues currently hampering the use of these proteins for therapeutic purposes.

The Protein Engineering group has constructed new ribonucleases variants with improved thermal stability by adding disulphide bonds by site-directed mutagenesis. Of particular interest is the variant NLSPE5Cys3, that features a 17ºC increase in its thermal stability without affecting the catalytic activity nor its cytotoxicity for ovary and lung cancer cell lines. This ribonuclease variant is also more resistant to proteolysis, suggesting that it may possess a relatively high half-live once administered in vivo.

All together Roura et al. conclude that this protein is an interesting candidate to be analysed as antitumor drug, and in the near future studies in vivo to prove this use are planned. The results of this study have been published in the article “Construction of Highly Stable Cytotoxic Nuclear-Directed Ribonucleases” available at the journal Molecules. Access to the original paper can be found at: https://www.mdpi.com/1420-3049/23/12/3273