During the last decade, paleoproteomics allowed us to open a direct window into the biological past, improving our understanding of the phylogenetic relationships of extant and extinct species, past human diseases, and reconstruction of the human diet. In particular, meta-proteomic studies, mainly carried out on ancient human dental calculus, provided insights into past oral microbial communities and ancient diets. On the contrary, very few investigations regard the analysis of ancient gut microbiota, which may enable a greater understanding of how microorganisms and their hosts have co-evolved and spread under the influence of changing diet practices and habitat. In this respect, this paper reports the results of the first-ever meta-proteomic analysis carried out on a gut tissue sample some 40,000 years old. Proteins were extracted by applying EVA (ethylene–vinyl acetate) films to the surface of the gut sample of a woolly mammoth (Mammuthus primigenus), discovered in 1972 close to the Shandrin River (Yakutia, Russia), and then investigated via a shotgun MS-based approach. Proteomic and peptidomic analysis allowed in-depth exploration of its meta-proteome composition. The results were validated through the level of deamidation and other diagenetic chemical modifications of the sample peptides, which were used to discriminate the “original” endogenous peptides from contaminant ones. Overall, the results of the meta-proteomic analysis here reported agreeing with the previous paleobotanical studies and with the reconstructed habitat of the Shandrin mammoth and provided insight into its diet. The data have been deposited to the ProteomeXchange with identifier < PXD025518 > .

Introduction: Capture of proteins and metabolites from Cultural Heritage (paintings, manuscripts, parchment etc.) has been done in the past via surface scraping and erasing, a method discouraged. The EVA (ethylene vinyl acetate) method consists of a plastic polymer in which strong cation and anion resins, admixed with C₈ and/or C₁₈, are embedded. Areas covered: We review here the findings on different items stored in public libraries and archives: (a) the original manuscript of the novel Master y Margarita by Bulgakov; (b) the death registries of the lazaretto in the 1630 Milano plague; (c) the shirt worn by A. Chekhov in his death bed; (d) Kepler’s script on Hipparchus (in St. Petersburg National Archives); (e) the Memoirs of G. Casanova. Expert opinion: The technique here surveyed appears to be a unique tool enabling exploration of any document stored in public archives, museum and private collections without damaging or contaminating the items under analysis. The amounts harvested from any surface are very minute, yet sufficient for analysis via advanced mass spectrometry instrumentation, thus permitting the identification of all captured material. It is hoped that the present review will stimulate the scientific community to adopt it for projects pertaining to Cultural Heritage.

We suggest to augment standard isoelectronic focusing for separation of proteins in a gradient of pH by a similar focusing in the presence of a strongly charged polyelectrolyte (PE). Proteins which have the same isoelectric point but different "hidden" charge of both signs in pI point make complexes with PE, which focus in different pH. This is a result of charge inversion of such proteins by adsorbed PE molecules, which is sensitive to the hidden charge. Hence the hidden charge is a new separation parameter

On 7 September 1191, a fierce battle took place in Arsuf (Palestine) between the Crusaders (marching south towards Jerusalem) led by King Richard the Lionheart and the Ayyubid army commanded by the sultan Saladin. The confrontation lasted for most of the day and terminated with a victory of the Crusaders, proving Richard’s courage as a soldier and his skill as a commander while denting Saladin’s reputation as an invincible warrior. The site (today known as Apollonia) holds the ruins of a Crusader castle perched on a cliff over the sea. We recovered plenty of pottery shards among which we could distinguish those of the Crusaders from those of the Ayyubid army. Extraction of food remnants confirmed that the Crusaders’ diet consisted mostly of pig and sheep meat (together with cheese), with a minimum of carbohydrates (what today would be termed a “ketogenic” diet), whereas the Muslim army consumed mostly carbohydrates (wheat, Triticum durum, Hordeum vulgare), together with fruits and vegetables, with minimal levels of sheep meat and cheese. As a result, the Crusaders’ diet had a positive effect on their slenderness and “cardio”. This might have been why the Ayyubid army lost ca. 10 times more soldiers in Arsuf. Shrewdness of leaders and soldiers’ equipment and willingness to fight are, of course, the main ingredients of victory, but diet too might not have a secondary role and help to tip the balance.