Chicken Plasminogen

In 2008, V.Ya. Shevchenko and S.V. Krivovichev built the zeolites series related to paulingite based on the inorganic gene concept and predicted a new zeolite named ISC-1 (Institute of Silicate Chemistry-1) [1]. The structure and composition of ISC-1 are described in detail in [2]. The found chemical formula of the new zeolite ISC-1 is Na14K24Al38Si202O48 center dot nH(2)O. Further research on the principles of assembly of zeolites and prediction of another previously unknown zeolite, ISC-2 (Institute of Silicate Chemistry-2), and the conditions of its formation are presented in [3-5]. The combinatorial-topological analysis of the crystal structure of the new aluminosilicate zeolite ISC-1 with cubic cell parameters a = 25.039 angstrom, V = 15 699 angstrom(3), and spatial group Imm is performed by computer-based methods (ToposPro software package) [6]. The topological type of the framework composed of bonded ?-(Si,Al)O-4 tetrahedra is characterized by a combination of polyhedral tilings: t-grc (48 T-atoms), t-pau (32 T-atoms), t-plg (30 T-atoms),t-opr (16 T- atoms), and t-oto (16 T- atoms). A framework-forming precursor for zeolites of 30 T-tetrahedra, which corresponds to the t-plg tile and contains an organic template Me-2-DABCO (N,N-dimethyl-1,4-diazabicyclo[2.2.2]octane), is established by the complete decomposition of the 3D atomic lattice into cluster structures. t-plg nanoclusters with the symmetry g = m are characterized by 4-, 6-, and 8-rings and the n-hedral symbol [4(6). 6(2). 8(6)]. Na-spacers statistically occupy neighboring positions in the 8-ring and between the 4-rings of the neighboring t-plg clusters. The basic 3D lattice type indicative of t-plg clusters center-of-gravity positions correspond to a simple cubic lattice with CN = 6. The self-assembly code of the 3D structure from complementary bonded nanoclusters-precursors is simulated in its entirety: primary chain microlayer framework. The doubled distance between t-plg clusters centers corresponds to the cubic cell translation vector a = 25.039 angstrom.

Schistosomiasis is a neglected tropical disease caused by trematodes of the genus Schistosoma which have a complex life cycle characterized by an asexual multiplication phase in the snail intermediate host and a sexual reproduction phase in the mammalian definitive host. The initial steps of the human host infection involve the secretion of proteins contained in the acetabular glands of cercariae that promote parasite adhesion and proteolysis of the skin layers. Herein, we performed a functional analysis of SmVAL18, identified as one of the three SCP/TAPS proteins constituent of cercarial secretions. We evaluated the SmVAL18 binding to immobilized macromolecules of the extracellular matrix (ECM) and to plasma components. Recombinant protein, expressed in E. coli, was found to maintain an ordered secondary structure typical of the SCP/TAPS domain after purification. Expression of native SmVAL18 protein was verified to be restricted to cercariae and 3-h schistosomula stages; furthermore, the protein was observed in the corresponding secretions, confirming that SmVAL18 is secreted during the first 3 h of in vitro culture. rSmVAL18 was able to interact specifically with plasminogen (PLG) and enhance its conversion into plasmin in the presence of the urokinase-type plasminogen activator (uPA). Protein homology modelling suggested that the PLG-rSmVAL18 interaction was mediated by lysine residues of the protein. This was supported by in vitro data using the lysine analogue, 6-aminocaproic acid (ACA), which abolished the interaction. Finally, our results showed that both cercariae and 3-h schistosomula, as well as their corresponding secretions, exhibited the capacity to bind PLG and enhance its conversion into plasmin in vitro in the same way as observed for the recombinant protein. In conclusion, our findings show that SmVAL18 is a novel PLG-binding protein secreted during the early stages of the mammalian-host infection.