Kinetic Interaction Analysis of Human Interleukin 5 Receptor α Mutants Reveals a Unique Binding Topology and Charge Distribution for Cytokine Recognition

Human interleukin 5 receptor alpha (IL5Ralpha) comprises three fibronectin type III domains (D1, D2, and D3) in the extracellular region. Previous results have indicated that residues in the D1D2 domains are crucial for high affinity interaction with human interleukin 5 (IL5). Yet, it is the D2D3 domains that have sequence homology with the classic cytokine recognition motif that is generally assumed to be the minimum cytokine-recognizing unit. In the present study, we used kinetic interaction analysis of alanine-scanning mutational variants of IL5Ralpha to define the residues involved in IL5 recognition. Soluble forms of IL5Ralpha variants were expressed in S2 cells, selectively captured via their C-terminal V5 tag by anti-V5 tag antibody immobilized onto the sensor chip and examined for IL5 interaction by using a sandwich surface plasmon resonance biosensor method. Marked effects on the interaction kinetics were observed not only in D1 (Asp(55), Asp(56), and Glu(58)) and D2 (Lys(186) and Arg(188)) domains, but also in the D3 (Arg(297)) domain. Modeling of the tertiary structure of IL5Ralpha indicated that these binding residues fell into two clusters. The first cluster consists of D1 domain residues that form a negatively charged patch, whereas the second cluster consists of residues that form a positively charged patch at the interface of D2 and D3 domains. These results suggest that the IL5 x IL5Ralpha system adopts a unique binding topology, in which the cytokine is recognized by a D2D3 tandem domain combined with a D1 domain, to form an extended cytokine recognition interface

Preparation and evaluation of Mn3GaN1-x thin films with controlled N compositions

Thin films of antiperovskite Mn3GaN1-x were grown on MgO (001) substrates by reactive magnetron sputtering, and their structural, magnetic, and magneto-optical properties were systematically investigated. It was found that the combination of the deposition rate and the N2 gas partial pressure could produce epitaxial films with a wide range of N composition (N-deficiency) and resulting c/a values (0.93 - 1.0). While the films with c/a = 0.992 - 1.0 were antiferromagnetic, the films with c/a = 0.93 - 0.989 showed perpendicular magnetic anisotropy (PMA) with the maximum PMA energy up to 1.5×106 erg/cm3. Systematic dependences of the energy spectra of the polar Kerr signals on the c/a ratio were observed, and the Kerr ellipticity was as large as 2.4 deg. at 1.9 eV for perpendicularly magnetized ferromagnetic thin films with c/a = 0.975. These results highlight that the tetragonal distortion plays an important role in magnetic and magneto-optical properties of Mn3GaN1-x thin films

北海道木古内湾におけるマコガレイ成魚の生活年周期

To clarify the annual life cycle of adult marbled sole Pleuronectes yokohamae in the coastal waters around Kikonai Bay, the seasonal changes in gonadosomatic index, hepatosomatic index, and condition factor of samples obtained with commercial set nets and research bottom trawl nets during May 1994 through October 1996 were examined. In addition, feeding intensity was investigated using a stomach contents index and noting the percentage of empty stomach. The annual life cycle of adult P. yokohamae was divided into the following three periods: spawning (February-April), active feeding and recovering (May-July), and inactive feeding (August-January). The inactive feeding period was further divided into two sub-periods: immature (August-October) and mature (November-January). It seems likely that P. yokohamae in this study area feeds intensively after spawning and matures under these high levels of nutrition.木古内湾に生息するマコガレイ成魚の生活年周期を明らかにするため，1994年5月から1996年10月までの期間，底建網と底曳網で得られた標本の生殖腺体指数 (GSI)，肝臓重量指数 (HSI)，肥満度 (CF)，胃内容物重量指数 (SCI)，空胃率の季節変化を検討した。GSIは雌雄ともに11月から増加して2月から4月にかけて著しく低下した。HSIとCFは雌雄ともに7月に最も高く，3月に最も低かった。SCIは5月に高く，11月と3月に低かった。また，空胃率は5月と7月に低く，11月と3月に高かった。以上から，本種成魚の生活年周期は産卵期（2-4月），摂餌盛期・回復期（5-7月），摂餌緩慢期（8-1月）の3期に区分され，さらに摂餌緩慢期は未成熟期（8-10月）と成熟期（11-1月）に分けられた。当海域はマコガレイのほぼ最北の漁場であるが，津軽暖流水の流入により冬季間も温暖なため産卵後活発に摂餌を行い，良好な栄養状態のもとで成熟を開始すると判断された

Saroma-ko Lagoon Observations for sea ice Physico-chemistry and Ecosystems 2019 (SLOPE2019)

Saroma-ko Lagoon, located on the Okhotsk Sea coast of Hokkaido, is seasonally covered by flat, homogeneous, easily accessible and safe sea ice. As such, it proves a very useful experimental site for the study of sea ice processes, the inter-comparison of methods, the testing of equipment, and the training of researchers new to the Polar regions. In this contribution, we describe a physical, chemical, and ecosystem survey at Saroma-ko Lagoon, conducted over February 23-28, 2019 under the auspices of the SLOPE2019 (Saroma-ko Lagoon Observations for sea ice Physico-chemistry and Ecosystems 2019) program. Sea ice cores were collected to examine temperature, salinity, oxygen isotopic ratio, thin sections, and chemical and biological parameters such as carbonate chemistry, CH4, nutrients, chlorophyll a concentrations, and ice algae community assemblage. Broadband and spectral irradiance measurements were carried out above/under the sea ice, and different sensors were inter-compared at close positions and environments. Equipment such as spectrometers, air-sea ice CO2/CH4 flux chamber, and under-ice turbulent heat flux systems were tested for future Arctic and Antarctic expeditions. Finally, an artificial pool was dug into the sea ice to understand the effect of snow particles on ice growth and to compare the gas exchange process over sea ice with an ice-free water surface. Our SLOPE2019 field campaign activities provided useful information for inter-comparison work and future sea ice research in the polar oceans

Progress and Prospects of X-Ray Laser Research in QST

Recent progress made in the development of coherent x-ray sources and their applications in material science and laser processing in the National Institutes for Quantum and Radiological Science and Technology (QST) is presented herein. The upgrade of Ti:Sapphire laser for a grazing incidence pumping (GRIP) scheme was started, to further develop a coherent x-ray source. Investigating the applications of x-ray lasers, we observed temporal evolution of metal surface ablation using an x-ray laser probe, and the damage to an EUV mirror structure by the x-ray pulse irradiation

A protein engineering approach differentiates the functional importance of carbohydrate moieties of interleukin-5 receptor α

Human interleukin-5 receptor alpha (IL5R alpha) is a glycoprotein that contains four N-glycosylation sites in the extracellular region. Previously, we found that enzymatic deglycosylation of IL5R alpha resulted in complete loss of IL5 binding To localize the functionally important carbohydrate moieties, we employed site directed mutagenesis at the N-glycosylation sites (Asn(15), Asn(111), Asn(196), and Asn(224)). Because Asn-to-Gln mutagenesis caused a significant loss of structural integrity, we used diverse mutations to identify stability changes. We also rationally designed mutations at and around the N-glycosylation sites based on sequence alignment with mouse IL5R alpha and other cytokine receptors. These approaches were most successful at Asn(15), Asn(111), and Asn(224). In contrast, any replacement at Asn(196) severely reduced stability, with the N196T mutant having a reduced binding affinity for IL5 and diminished biological activity because of the lack of cell surface expression. Lectin inhibition analysis suggested that the carbohydrate at Asn(196) is unlikely involved in direct ligand binding Taking this into account, we constructed a stable variant, with triple mutational deglycosylation (N15D, I109V/V110T/N111D, and L223R/N224Q). The re-engineered protein retained Asn(196) while the other three glycosylation sites were eliminated. This mostly deglycosylated variant had the same ligand binding affinity and biological activity as fully glycosylated IL5R alpha, thus demonstrating a unique role for Asn(196) glycosylation in IL5R alpha function. The results suggest that unique carbohydrate groups in multiglycosylated receptors can be utilized asymmetrically for function