bioRxiv Science⌕ Search

Biology subjects

Rubini, M.

Publications and source records attributed to Rubini, M..

2 recordsLinked to original sources

Reading of ingroup politicians smiles triggers smiling in the corner of ones eyes

Capturing political support from spontaneous smile reactions detected in others faces can be used to gauge electorate preference. But will a smile elicited in the corner of ones eye while reading of a favored politician smiling indicate positive disposition and political support for target candidates? From an embodied simulation perspective, we tested whether reading of an ingroup or outgroup politician smiling would trigger morphologically different smiles in faces of readers. In a reading task in the laboratory, participants were presented with subject-verb phrases describing left and right-wing politicians smiling or frowning while their facial muscular reactions were measured via electromyography (EMG) recording from the zygomaticus major (ZM, lip puller muscle), orbicularis oculi (OO, eye corner muscle) and the corrugator supercili (CS, wrinkler of the eyebrows). We expected and found that participants responded with a smile detected at the lip puller (ZM) and eye corner (OO) facial muscles when exposed to portrayals of smiling politicians of same political orientation, and reported more positive emotions towards these latter. When reading about outgroup politicians smiling, there was a weaker activation of the lip corner (ZM) muscle and no activation of the eye corner (OO) muscle, while emotions reported towards outgroup politicians were significantly more negative. Also, a more enhanced frown response (CS) was found for ingroup compared to outgroup politicians frown expressions. Present findings suggest that a politicians smile may go a long way to influence electorates through both non-verbal and verbal pathways. They add another layer to our understanding of how language and social information shape embodied effects in a highly nuanced manner.

physiology↗

4-Thiaproline accelerates the slow folding phase of proteins containing cis prolines in the native state by two orders of magnitude

The cis/trans isomerization of peptidyl-prolyl peptide bonds is often the bottleneck of the refolding reaction for proteins containing cis proline residues in the native state. Proline (Pro) analogues, especially C4-substituted fluoroprolines, have been widely used in protein engineering to enhance the thermodynamic stability of peptides and proteins and to investigate folding kinetics. 4-thiaproline (Thp) has been shown to bias the ring pucker of Pro, to increase the cis population percentage of model peptides in comparison to Pro, and to diminish the activation energy barrier for the cis/trans isomerization reaction. Despite its intriguing properties, Thp has been seldom incorporated into proteins. Moreover, the impact of Thp on the folding kinetics of globular proteins has never been reported. In this study, we show that upon incorporation of Thp at cisPro76 into the thioredoxin variant Trx1P the half-life of the refolding reaction decreased from [~]2 hours to [~]35 seconds. A dramatic acceleration of the refolding rate could be observed also for the protein pseudo wild-type barstar upon replacement of cisPro48 with Thp. Quantum chemical calculations revealed that the replacement of the C{gamma}H2 group by a sulfur atom in the pyrrolidine ring, lowers the barrier for cis/trans rotation due to a weakened peptide bond. The protein variants retained their thermodynamic stability upon incorporation of Thp, while the catalytic and enzymatic activities of the modified Trx1P remained unchanged. Our results show that the Pro isostere Thp might eliminate the bottleneck of the refolding reaction of proteins containing cis proline residues in the native state, independent from the local structural environment.

biochemistry↗