Design of a mutation-integrated trimeric RBD with broad protection against SARS-CoV-2.

The continuous emergence of SARS-CoV-2 variants highlights the need of developing vaccines with broad protection. Here, according to the immune-escape capability and evolutionary convergence, the representative SARS-CoV-2 strains carrying the hotspot mutations were selected. Then, guided by structural and computational analyses, we present a mutation-integrated trimeric form of spike receptor-binding domain (mutI-tri-RBD) as a broadly protective vaccine candidate, which combined heterologous RBDs from different representative strains into a hybrid immunogen and integrated immune-escape hotspots into a single antigen.

catena-Poly[[diaqua-nickel(II)]-bis-(μ-2-{[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]sulfan-yl}acetato)].

In the title compound, [Ni(C(9)H(6)N(3)O(3)S)(2)(H(2)O)(2)](n), the Ni(II) atom, located on an inversion center, is ligated in an octa-hedral geometry by two carboxyl-ate O atoms from two 2-{[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]sulfan-yl}acetate (L) ligands and two O atoms from water mol-ecules in the equatorial plane, and two pyridine N atoms from other two L ligands at the apical sites. Two L ligands bridge pairs of metal atoms in an anti-parallel manner, forming centrosymmetric dinuclear quasi-recta-ngular units which are linked into infinite double-stranded chains parallel to [100]. O-H⋯O hydrogen bonds between the coordinating water mol-ecules and the carboxyl-ate groups of the L ligand as well as interchain S⋯N inter-actions [2.

Tetra-aqua-bis-[3-(pyridin-4-yl)benzoato-κN]manganese(II).

In the title compound, [Mn(C(12)H(8)NO(2))(2)(H(2)O)(4)], the Mn(2+) ion lies on a twofold rotation axis and has a distorted N(2)O(4) octa-hedral coordination geometry formed by four water O atoms in the equatorial plane and two apical pyridyl N atoms. A three-dimensional network is formed in the crystal structure by multiple O-H⋯O hydrogen bonds between the coordin-ating water molecules and the free carboxylate groups.