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

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 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

Erosion control effect of red soil such as Kunigami mji soil by the addition of soil conditioner

Kunigami maji soil is a red soil that distributes in the central north of the main island of Okinawa Prefecture, Since this soil is abundant in fine particles and poor in coagulation force, it is extremely vulnerable to water, causing severe soil runoff when it faces rainfall. The muddy water generated by soil runoff inflicts serious effects on downstream territories, farm fields, rivers and oceans. Muddy water is factor to pollute water environment and destroy ecosystem. This research used a soil conditioner to control soil loss, and examined its control effect. As the soil conditioner, E-soiru was used. In an experiment using artificial rainfall, the amount of dispersed soil occupied about 20-30% of the amount of eroded soil, showing that this factor cannot be neglected. By blending E-soiru, the amount of eroded soil decreased by 39-92% at an inclination of 1.7° and by 59-89% at an inclination of 8.0°. The result showed the significant effect of the addition of E-soiru on soil loss control. In particular, when the volume ratio of Kunigami maji soil and E-soiru was at 1:05, the mixture showed the maximum effect

Biochemical characterization of Acacia schweinfurthii serine proteinase inhibitor

One of the many control mechanisms of serine proteinases is their specific inhibition by protein proteinase inhibitors. An extract of Acacia schweinfurthii was screened for potential serine proteinase inhibition. It was successfully purified to homogeneity by precipitating with 80% (v/v) acetone and sequential chromatographic steps, including ion-exchange, affinity purifica- Q2 tion and RP-HPLC. Reducing SDS-PAGE conditions revealed an inhibitor (ASTI) consisting of two polypeptide chains A and B of approximate molecular weights of 16 and 10 kDa, respectively, and under non-reducing conditions, 26 kDa was observed. The inhibitor was shown to inhibit bovine trypsin (Ki of 3.45 nM) at an approximate molar ratio of inhibitor: trypsin (1:1). The A- and B-chains revealed complete sequences of 140 and 40 amino acid residues, respectively. Sequence similarity (70%) was reported between ASTI A-chain and ACTI A-chain (Acacia confusa) using the ClustalW. The B-chain produced a 76% sequence similarity between ASTI and Leucaena leucocephala trypsin inhibitor

ショクドウ ソウカン ニヨル フンゴウブ カンゼン リカイ オ カイケッチョウ サイケン デ シュウフクシタ ショクドウ セツジョ ノ 1レイ

症例は60 歳代, 男性. 身長162.6 cm, 体重40.0 kg, Body Mass Index（BMI）15.1 kg / m2であり, 既往歴に慢性閉塞性肺疾患（COPD）を認めた. 胸部上部食道癌 T1b N0 M0 Stage Iに対して食道亜全摘, 3領域リンパ節郭清, 胸骨後胃管再建を施行した.術当日に抜管したが, 術後肺炎に伴う呼吸不全のため, 術後6日目に気管内挿管を試みたが、食道挿管となった．再挿管, 人工呼吸管理の後に軽快し術後13日目に抜管となったが, 術後透視で吻合部周囲に造影剤漏出を認めた. 2ヶ月間の保存的加療で造影剤漏出は消失したが吻合部に長径4 cmの高度狭窄を認めた．内視鏡的拡張術での改善は困難であり, 術後243日目に消化管再建術を施行した. 手術所見として, 第2肋間より頭側の胸骨を切除したところ, 胃管の口側断端は第2肋間の高さの胸骨後面に位置していた.食道断端までは肉芽で置換されていた.胸骨前経路回結腸再建を施行し, 再建術後 8日目に食事を開始し, 合併症なく再建術後30日目に退院となった. 回結腸再建後2年経過後も食道癌の再発は認めず, 通過障害なく経口摂取のみでの生活が可能となっている．A 60s-year-old man underwent endoscopic screening during which a tumor was detected in the upper thoracic esophagus, which was diagnosed as T1bN0M0 Stage I esophageal squamous cell carcinoma. He had a history of chronic obstructive pulmonary disease. He underwent subtotal esophagectomy with 3 field lymph node dissection. Reconstruction was performed by gastric tube through the posterior sternal route. Extubation was performed on the day of surgery. Respiratory failure by postoperative pneumonia occurred, and ventilatory management was performed on the sixth postoperative day. However, the intubation was put into the esophagus. He became well and extubation was performed on the 13th postoperative day. Postoperative fluoroscopy showed contrast leakage around the anastomotic site. After 2 months of conservative treatment, the contrast leak disappeared, but there was a severe stenosis of 4 cm in length at the anastomosis. Endoscopic dilatation was not sufficient to improve the stenosis. Gastrointestinal reconstruction was performed on the 243rd postoperative day. The cephalic sternum was resected, and the gastrointestinal canal opening margin was located on the posterior surface of the sternum, at the level of the second intercostal space. The segment was replaced by a granulation. The patient underwent anterior sternal ileocolic reconstruction. Oral intake started on the 8th day after the reconstruction, and hospital discharge was on the 30 th day after the reconstruction without any complications. Two years after ileocolic reconstruction, there has been no cancer recurrence, and he lives well on oral intake only