CAṄKA ILAKKIYATTIL VĀṈIYAL [ASTRONOMY IN SANGAM LITERATURE]

Tamil science is the knowledge that has traditionally been developed, used and explained scientifically by Tamils. It also refers to the contribution that Tamil is making to science today. Tamil science is found in many fields such as linguistics, medicine, architecture, agriculture, biology, mathematics and astronomy. It is noteworthy that the Tamils ​​who had various technologies also had the basic science for it. Sangam literature is interspersed with versatile messages. Admired as world literature, it contains news from a variety of disciplines. It is known that the Sangam periodicals became versatile due to this. Many world scholars have studied and praised the astronomical news found by the Tamils. Tamils ​​refer to those who know astronomy as 'virgins'. Literary evidence also suggests that the computer predicts time with the motions of a planet orbiting in the sky. The literature is a testament to the fact that Tamils ​​are the ones who know the scientific method of measuring the planets and atmospheres of the sky, their movements and time scales. The Sangam poets knew that there were various planets and galaxies in the sky. News about the Sun, Earth, Jupiter, Mercury, Venus, Saturn, and the satellite Moon is found in the association songs. News about dental galaxies has also been reported in Sangam literature. It is also possible to know that the Tamils ​​who guided the polar fish at night knew the four directions during the day with the help of the sun.

Crystal structure of an insect antifreeze protein reveals ordered waters on the ice-binding surface

Antifreeze proteins (AFPs) are characterized by their ability to adsorb to the surface of ice crystals and prevent any further crystal growth. AFPs have independently evolved for this purpose in a variety of organisms that encounter the threat of freezing, including many species of polar fish, insects, plants and microorganisms. Despite their diverse origins and structures, it has been suggested that all AFPs can organize ice-like water patterns on one side of the protein (the ice-binding site) that helps bind the AFP to ice. Here, to test this hypothesis, we have solved the crystal structure at 2.05 Å resolution of an AFP from the longhorn beetle, Rhagium mordax with five molecules in the unit cell. This AFP is hyperactive, and its crystal structure resembles that of the R. inquisitor ortholog in having a β-solenoid fold with a wide, flat ice-binding surface formed by four parallel rows of mainly Thr residues. The key difference between these structures is that the R. inquisitor AFP crystallized with its ice-binding site (IBS) making protein–protein contacts that limited the surface water patterns. Whereas the R. mordax AFP crystallized with the IBSs exposed to solvent enabling two layers of unrestricted ordered surface waters to be seen. These crystal waters make close matches to ice lattice waters on the basal and primary prism planes.

A polyalanine peptide derived from polar fish with anti-infectious activities

Due to the growing concern about antibiotic-resistant microbial infections, increasing support has been given to new drug discovery programs. A promising alternative to counter bacterial infections includes the antimicrobial peptides (AMPs), which have emerged as model molecules for rational design strategies. Here we focused on the study of Pa-MAP 1.9, a rationally designed AMP derived from the polar fish Pleuronectes americanus. Pa-MAP 1.9 was active against Gram-negative planktonic bacteria and biofilms, without being cytotoxic to mammalian cells. By using AFM, leakage assays, CD spectroscopy and in silico tools, we found that Pa-MAP 1.9 may be acting both on intracellular targets and on the bacterial surface, also being more efficient at interacting with anionic LUVs mimicking Gram-negative bacterial surface, where this peptide adopts α-helical conformations, than cholesterol-enriched LUVs mimicking mammalian cells. Thus, as bacteria present varied physiological features that favor antibiotic-resistance, Pa-MAP 1.9 could be a promising candidate in the development of tools against infections caused by pathogenic bacteria.

Quantitative study on the antifreeze protein mimetic ice growth inhibition properties of poly(ampholytes) derived from vinyl-based polymers

Antifreeze (glyco) proteins (AF(G)Ps) from the blood of polar fish species are extremely potent ice recrystallization inhibitors (IRI), but are difficult to synthesise or extract from natural sources.