Involvement of loop 5 lysine residues and the N-terminal β-hairpin of the ribotoxin hirsutellin A on its insecticidal activity

Ribotoxins are cytotoxic members of the family of fungal extracellular ribonucleases best represented by RNase T1. They share a high degree of sequence identity and a common structural fold, including the geometric arrangement of their active sites. However, ribotoxins are larger,with a well-defined N-terminal β-hairpin, and display longer and positively charged unstructured loops. These structural differences account for their cytotoxic properties.Unexpectedly, the discovery of hirsutellin A (HtA), a ribotoxin produced by the invertebrate pathogen Hirsutella thompsonii, showed how it was possible to accommodate these features into a shorter amino acid sequence. Examination of HtA N-terminal β-hairpin reveals differences in terms of length, charge, and spatial distribution. Consequently,four different HtA mutants were prepared and characterized. One of them was the result of deleting this hairpin [Δ(8-15)] while the other three affected single Lys residues in its close spatial proximity (K115E, K118E, and K123E). The results obtained support the general conclusion that HtA active site would show a high degree of plasticity,being able to accommodate electrostatic and structural changes not suitable for the other previously known larger ribotoxins, as the variants described here only presented small differences in terms of ribonucleolytic activity and cytotoxicity against cultured insect cells.

Fashion films as a new communication format to build fashion brands

The consolidation of collaborative video platforms such as YouTube and Vimeo in recent years has significantly changed the way fashion brands communicate with their audiences. Fashion films have emerged as a new and revolutionary tool adopted by luxury brands at the start of the XXI Century to construct their brands. A sample of 62 fashion films from 2006 to 2016 was analyzed in order to describe fashion film’s anatomy and its main characteristics that constitute an especial type of branded content, originated by brands in their quest for exclusivity and authenticity. As a distinctive type of experiential marketing mostly used by luxury fashion brands, they would become a new communication strategy for mainstream brands, but also allow the discovery of a profound connection with consumers through audiovisual narration.