Artificial O2 Carrier with Antioxidant Activities

A covalent core–shell structured protein cluster composed of hemoglobin (Hb) at the center and human serum albumins (HSA) at the periphery, Hb-HSAm, is an artificial O2 carrier that can function as a red blood cell substitute. Here we described the preparation of a novel Hb-HSA3 cluster with antioxidant activities and its O2 complex stable in aqueous H2O2 solution. We used an approach of incorporating a Pt nanoparticle (PtNP) into the exterior HSA unit of the cluster. A citrate reduced PtNP (1.8 nm diameter) was bound tightly within the cleft of free HSA with a binding constant (K) of 1.1×107 M−1, generating a stable HSA-PtNP complex. This platinated protein showed high catalytic activities for dismutations of superoxide radical anions (O2•–) and hydrogen peroxide (H2O2), i.e., superoxide dismutase and catalase activities. Also, Hb-HSA3 captured PtNP into the external albumin unit (K = 1.1×107 M−1), yielding an Hb-HSA3(PtNP) cluster. The association of PtNP caused no alteration of the protein surface net charge and O2 binding affinity. The peripheral HSA-PtNP shell prevents oxidation of the core Hb, which enables the formation of an extremely stable O2 complex, even in H2O2 solution

〓

This paper is a case report for the author\u27s class on Japanese social behavior : Japanese ways of thinking and behavior. The course is offered primarily to international students from western countries as a Japanese studies program at the Institute for Japanese Studies at Nagoya Gakuin University. This paper covers the outline of my course from (1) course planning : students\u27 attribution, research method, texts (2) references (3) class management (4) conclusion, and (5) appendix-syllabus. The important issues are how to program an effective course work, how to identify students\u27 needs and academic background, effective research method, selection of effective texts and references, and effective program management. Since this area of study requires an interdisciplinary approach, the author sets frameworks for effective teaching and learning. The first framework for research includes four factors, i.e. understanding the self, understanding others, understanding one\u27s own culture and society, and learning the foreign culture and society. The second framework is the traditional ideas, i.e. up and down relations, tatemae and honne, give and receive relations, front versus rear, and public versus private. The third framework is on the social attribution, i.e., gender, age and social position. These frameworks interact with each other to create cultural enforcements which shape Japanese social behaviors

Crystal structural analysis of human serum albumin complexed with hemin and fatty acid

BACKGROUND: Human serum albumin (HSA) is an abundant plasma protein that binds a wide variety of hydrophobic ligands including fatty acids, bilirubin, thyroxine and hemin. Although HSA-heme complexes do not bind oxygen reversibly, it may be possible to develop modified HSA proteins or heme groups that will confer this ability on the complex. RESULTS: We present here the crystal structure of a ternary HSA-hemin-myristate complex, formed at a 1:1:4 molar ratio, that contains a single hemin group bound to subdomain IB and myristate bound at six sites. The complex displays a conformation that is intermediate between defatted HSA and HSA-fatty acid complexes; this is likely to be due to low myristate occupancy in the fatty acid binding sites that drive the conformational change. The hemin group is bound within a narrow D-shaped hydrophobic cavity which usually accommodates fatty acid; the hemin propionate groups are coordinated by a triad of basic residues at the pocket entrance. The iron atom in the centre of the hemin is coordinated by Tyr161. CONCLUSION: The structure of the HSA-hemin-myristate complex (PDB ID 1o9x) reveals the key polar and hydrophobic interactions that determine the hemin-binding specificity of HSA. The details of the hemin-binding environment of HSA provide a structural foundation for efforts to modify the protein and/or the heme molecule in order to engineer complexes that have favourable oxygen-binding properties

ホッカイドウアバシリトウブチイキ ニ オケル カサイリュウタイセキブツ ニ フクマレル アパタイトリンサン ノ ヒョウカ ト ソノ ノウギョウリヨウ

北海道網走地域では,ほぼ全域に火山放出物である屈斜路火砕流堆積物が分布している。同地域において,大規模畑作圃場の多くが,基盤整備事業において均平化のための地形修正を受けた結果,作土下にこの火砕流堆積物からなる下層土を持つことが知られている。この火砕流層は,作物根の下層土への発達を阻害するため生産性を向上する上で問題となっている。しかし一方で,火山放出物の多くはリン鉱物であるアパタイトを含むことから,この火砕流層は潜在的なリン資源としても期待できる。そこで,網走市東部の地形修正を受けた圃場,および同地域内の自然林下から採取された火砕流堆積物について,リン酸の化学形態を調査し,リン資源としての評価を行なった。同時に,圃場においてこの火砕流層と作土とを全層混合することにより,リン酸肥沃度を向上しうるかについて,テンサイ栽培試験により検討した。その結果,網走地域の火砕流堆積物中にはアパタイト形態のリン酸が400-1000mg P2O5 kg-1程度含まれ,このうち70-170mg P2O5 kg-1程度が可給態リン酸として評価された。このリン酸量は北海道のリン酸肥沃度改良目標値に匹敵する。この火砕流層を作土と全層混合することにより,テンサイのリン酸吸収量は50%増加し,糖収量も30%増加したことから,網走地域の火砕流堆積物は農業上有用なリン資源として活用できると考えられる。In Abashiri district, in the eastern part of Hokkaido, much arable land that has been leveled for agricultural use has subsoil layers that consist of Kutcharo pyroclastic flow deposits. Kutcharo pyroclastic flow deposits in subsoil were generally compacted by land leveling, so that penetration resistance is too high to allow the root development of arable crops. However, the available phosphate (Truog-P) content is high (70-170mg P2O5 kg-1). Thus, the chemical forms of phosphorus (P) in the pyroclastic flow deposits were evaluated using the selective extraction of each form of phosphorus, i.e. Al-bound, Fe-bound and Ca-bound P (Al-P, Fe-P, Ca-P). The utilization of the phosphorus in the pyroclastic flow deposits was also investigated in a field cultivation experiment. Sugar beet was grown in a field with pyroclastic flow deposits in subsoil. Two years ago at the start of the experiment, trenchers were used to thoroughly mix pyroclastic flow subsoil with top soil in a part of the field to improve the root development (subsoil mixed plot) and the rest of the field was used as a control plot. It was determined that most of the P in the pyroclastic flow deposits was in the Ca-P form. It is well known that volcanic tephra contains the mineral apatite. Therefore, the high Truog-P content of Kutcharo pyroclastic flow deposits should be due to the presence of apatite. The field cultivation experiment showed that subsoil mixing clearly improved root development in the subsoil. The phosphorus uptake was 50% higher for the deep cultivated plot than the control plot. This suggested that the sugar beet roots utilized the apatite-P in their root development. Although the presence of the pyroclastic flow deposits has been a limiting factor for agricultural productivity, the apatite-P should be an important resource which can improve agricultural activities in Abashiri district

Distribution and Translocation of Carbohydrates in Italian Ryegrass (Lolium multiflorum Lam.) during Ear Development

書誌情報のみBibliographic data Onl