Structures and Functions of C-type Lectins in Marine Invertebrates

Lectins distributing in all animal phyla form a diverse group of protein families that have in common the ability to recognize and bind certain carbohydrates. Although at least 13 animal lectin families are known to exist, many of marine invertebrate lectins are categorized in C-type lectin family, which was named from the Ca^-dependency for their carbohydrate binding activities. In contrast to a growing list of C-type lectins in marine invertebrates, their physiological roles are not fully understood. This review summarizes the structures and functions of marine invertebrate C-type lectins with our new findings

A case of histoplasmosis Report 1. Cinical, mycological and pathological observations

In our country it has been believed that there is no histoplasmosis here in Japan. However, from the above clinical signs, radiological characteristics, laboratory tests, pathological and mycological examinations, and experimental findings, we believe this is the first case of histoplasmosis in Japan.</p

Diversified Carbohydrate-Binding Lectins from Marine Resources

Marine bioresources produce a great variety of specific and potent bioactive molecules including natural organic compounds such as fatty acids, polysaccharides, polyether, peptides, proteins, and enzymes. Lectins are also one of the promising candidates for useful therapeutic agents because they can recognize the specific carbohydrate structures such as proteoglycans, glycoproteins, and glycolipids, resulting in the regulation of various cells via glycoconjugates and their physiological and pathological phenomenon through the host-pathogen interactions and cell-cell communications. Here, we review the multiple lectins from marine resources including fishes and sea invertebrate in terms of their structure-activity relationships and molecular evolution. Especially, we focus on the unique structural properties and molecular evolution of C-type lectins, galectin, F-type lectin, and rhamnose-binding lectin families

Protein Transduction Method for Cerebrovascular Disorders

Many studies have shown that a motif of 11 consecutive arginines (11R) is one of the most effective protein transduction domains (PTD) for introducing proteins into the cell membrane. By conjugating this &#34;11R&#34;, all sorts of proteins can effectively and harmlessly be transferred into any kind of cell. We therefore examined the transduction efficiency of 11R in cerebral arteries and obtained results showing that 11R fused enhanced green fluorescent protein (11R-EGFP) immediately and effectively penetrated all layers of the rat basilar artery (BA), especially the tunica media. This method provides a revolutionary approach to cerebral arteries and ours is the first study to demonstrate the successful transductionof a PTD fused protein into the cerebral arteries. In this review, we present an outline of our studies and other key studies related to cerebral vasospasm and 11R, problems to be overcome, and predictions regarding future use of the 11R protein transduction method for cerebral vasospasm (CV).</p

Study of superconductivity of very thin FeSe1−xTex\mathrm{FeSe}_{1-x}\mathrm{Te}_x films investigated by microwave complex conductivity measurements

Complex conductivity measurements spanning the entire temperature range, including the vicinity of $T_c$, were conducted on systematically varied FeSe$_{1-x}$Te$_x$ ($x$ = 0 - 0.5) very thin films. By applying a novel cavity measurement technique employing microwave electric fields parallel to FeSe$_{1-x}$Te$_x$ films, we observed distinct temperature-dependent alterations in superfluid fraction and quasiparticle scattering rate at the nematic boundary. These changes in the nematic boundary suggests variations in the superconducting gap structure between samples in the nematic and non-nematic phase. Moreover, fluctuation is visible up to 1.2 $T_c$ irrespective of nematic order, consistent with large superconducting fluctuations in iron chalcogenide superconductors reported previously in [H. Takahashi $\textit{et al}$, Phys. Rev. B 99, 060503(R) (2019)] and [F. Nabeshima $\textit{et al}$, Phys. Rev. B 97, 024504(R) (2018)]

Protein engineering of conger eel galectins by tracing of molecular evolution using probable ancestral mutants

<p>Abstract</p> <p>Background</p> <p>Conger eel galectins, congerin I (ConI) and congerin II (ConII), show the different molecular characteristics resulting from accelerating evolution. We recently reconstructed a probable ancestral form of congerins, Con-anc. It showed properties similar to those of ConII in terms of thermostability and carbohydrate recognition specificity, although it shares a higher sequence similarity with ConI than ConII.</p> <p>Results</p> <p>In this study, we have focused on the different amino acid residues between Con-anc and ConI, and have performed the protein engineering of Con-anc through site-directed mutagenesis, followed by the molecular evolution analysis of the mutants. This approach revealed the functional importance of loop structures of congerins: (1) N- and C-terminal and loop 5 regions that are involved in conferring a high thermostability to ConI; (2) loops 3, 5, and 6 that are responsible for stronger binding of ConI to most sugars; and (3) loops 5 and 6, and Thr38 residue in loop 3 contribute the specificity of ConI toward lacto-<it>N</it>-fucopentaose-containing sugars.</p> <p>Conclusions</p> <p>Thus, this methodology, with tracing of the molecular evolution using ancestral mutants, is a powerful tool for the analysis of not only the molecular evolutionary process, but also the structural elements of a protein responsible for its various functions.</p