The Topology,in Model Membranes,of the Core Peptide Derived from the T‐Cell Receptor Transmembrane Domain

The T‐cell receptor–CD3 complex (TCR–CD3) serves a critical role in protecting organisms from infectious agents. The TCR is a heterodimer composed of α‐ and β‐chains, which are responsible for antigen recognition. Within the transmembrane domain of the α‐subunit, a region has been identified to be crucial for the assembly and function of the TCR. This region, termed core peptide (CP), consists of nine amino acids (GLRILLLKV), two of which are charged (lysine and arginine) and are crucial for the interaction with CD3. Earlier studies have shown that a synthetic peptide corresponding to the CP sequence can suppress the immune response in animal models of T‐cell‐mediated inflammation, by disrupting proper assembly of the TCR. As a step towards the understanding of the source of the CP activity, we focused on CP in egg phosphatidylcholine/cholesterol (9:1, mol/mol) model membranes and determined its secondary structure, oligomerization state, and orientation with respect to the membrane. To achieve this goal, 15‐residue segments of TCRα, containing the CP, were synthesized and spin‐labeled at different locations with a nitroxide derivative. Electron spin‐echo envelope modulation spectroscopy was used to probe the position and orientation of the peptides within the membrane, and double electron–electron resonance measurements were used to probe its conformation and oligomerization state. We found that the peptide is predominantly helical in a membrane environment and tends to form oligomers (mostly dimers) that are parallel to the membrane plane.     

Alpha‐Synuclein Binds to the Inner Membrane of Mitochondria in an α‐Helical Conformation

The human alpha‐Synuclein (αS) protein is of significant interest because of its association with Parkinson's disease and related neurodegenerative disorders. The intrinsically disordered protein (140 amino acids) is characterized by the absence of a well‐defined structure in solution. It displays remarkable conformational flexibility upon macromolecular interactions, and can associate with mitochondrial membranes. Site‐directed spin‐labeling in combination with electron paramagnetic resonance spectroscopy enabled us to study the local binding properties of αS on artificial membranes (mimicking the inner and outer mitochondrial membranes), and to evaluate the importance of cardiolipin in this interaction. With pulsed, twofrequency, double‐electron electron paramagnetic resonance (DEER) approaches, we examined, to the best of our knowledge for the first time, the conformation of αS bound to isolated mitochondria.     

A triple spin-labeling strategy coupled with DEER analysis to detect DNA modifications and enzymatic repair

In a spin: Spin-labeled oligonucleotides produced by click chemistry can be studied by EPR, by using a DEER sequence. This was used to test a complex triple-labeling strategy with damaged DNA. Extensive and accurate analysis of DNA structure and enzymatic repair processes were performed after digestion by EndoIV. Modified DNA structures and DNA-protein interactions can now be readily studied.     

重庆市公共建筑集中空调工程设计能效比限值(夏季)

根据空调工程设计能效比、冷量输配系统设计能效比、冷源系统设计能效比、水系统设计能效比、风系统设计能效比的概念及计算方法，结合四者之间的相关性分析，得出：只要对空调工程设计能效比和冷量输配系统设计能效比进行控制，就可以达到降低整个空调工程能耗、降低建筑能耗的目的；提出了夏季工况下，空调工程设计能效比和冷量输配系统设计能效比的限值。     

Distance determination in heterogeneous DNA model systems by pulsed EPR

Many biological systems, especially those based on nucleic acids, are structurally heterogeneous in solution. We demonstrate here the ability to measure multiple distances, of between 2 and 7 nm, from a heterogeneous mixture of double-spin-labeled DNA duplexes. We have constructed a DNA distance ruler based on the attachment of nitroxide spin labels to 2'-amino-modified nucleosides. The distribution of distances between the spin labels was obtained by Tikhonov regularization analysis of the dipolar coupling evolution data measured by using the electron paramagnetic resonance method, pulsed-electron double resonance (PELDOR). Optimization of the conditions and techniques used in the preparation of the samples has allowed us to increase the sensitivity and reduce aggregation artifacts. As a result, we have been able to demonstrate deconvolution of distances from structurally heterogeneous samples and show the limits of the technique by examining data derived from up to five DNA duplexes, in a single mixture, in which the concentration of each species was as low as 5 microM.     

Fatty Acid Triangulation in Albumins Using a Landmark Spin Label

Several spatial correlations of up to six fatty acid (FA) binding sites in albumins were found by double electron‐electron resonance (DEER). A strategy was used that combines spin‐labeling and spin‐probing techniques in electron paramagnetic resonance (EPR) spectroscopy. This is here achieved by introducing an additional covalent landmark spin (LS) label to the self‐assembled system of EPR‐active, paramagnetic stearic acid derivatives and albumins. Therefore, a cysteine specific, paramagnetic LS that was attached to the albumin surface at a unique position (Cys34) provides a fixed topological reference point for monitoring statistical ligand uptake. We propose that the determination of nanoscale distance distributions emerging between the LS and EPR‐active fatty acid derivatives generally allows for the direct observation of individually occupied binding sites in solution. Essentially, several binding pockets, groups of them and evidence for ligand‐induced allosteric modulation can be traced from such FA‐LS interspin correlations. Experimental results were substantiated with theoretical predictions from molecular dynamics (MD) simulations. It was observed that all binding sites in an albumin ensemble may be statistically filled even at the lowest level of ligand loading. This approach generally bears the potential for mapping occupation states of individual ligand binding sites in proteins using such spin‐labeled ligands.     

重庆市办公建筑空调工程设计能效比统计分析

提出了空调工程及其子系统设计能效比的计算方法,在对重庆市办公类公共建筑36个空调工程的设计情况进行调查统计的基础上,计算了冬、夏工况下空调工程的冷热源系统、水系统、风系统的设计能效比。分析了空调工程冷热源系统、水系统、风系统的设计能效比出现最大值、最小值的原因,探讨了设计能效比的平均值、偏差情况及提高设计能效比的途径。     

S.DEER与ONLY的品牌对比分析

选择S.DEER和ONLY两大服装品牌,对两者的品牌构成要素进行了对比,并采用SWOT法对他们进行分析,为中国女装品牌的发展提供了参考。