Isolation of a hemidesmosome-rich fraction from a human squamous cell carcinoma cell line

Hemidesmosomes are cell-to-matrix adhesion complexes anchoring keratinocytes to basement membranes. For the first time, we present a method to prepare a fraction from human cultured cells that are highly enriched in hemidesmosomal proteins. Using DJM-1 cells derived from human squamous cell carcinoma, accumulation of hemidesmosomes was observed when these cells were cultured for more than 10 days in a commercial serum-free medium without supplemental calcium. Electron microscopy demonstrated that numerous electron-dense adhesion structures were present along the basal cell membranes of DJM-1 cells cultured under the aforementioned conditions. After removing cellular materials using an ammonia solution, hemidesmosomal proteins and deposited extracellular matrix were collected and separated by electrophoresis. There were eight major polypeptides, which were determined to be plectin, BP230, BP180, integrin α6 and β4 subunits, and laminin-332 by immunoblotting and mass spectrometry. Therefore, we designated this preparation as a hemidesmosome-rich fraction. This fraction contained laminin-332 exclusively in its unprocessed form, which may account for the promotion of laminin deposition, and minimal amounts of Lutheran blood group protein, a nonhemidesmosomal transmembrane protein. This hemidesmosome-rich fraction would be useful not only for biological research on hemidesmosomes but also for developing a serum test for patients with blistering skin diseases.     

魔芋葡苷聚糖（KGM）凝胶为亲和层析载体与Sepharose4B的比较 …

将ＫＧＭ和Ｓｅｐｈａｒｏｓｅ ４Ｂ凝胶在相同条件下活化、偶联接上染料Ｃｉｂａｃｒｏｎ Ｂｌｕｅ Ｆ３ＧＡ制成了ＫＧＭ和Ｓｅｐｈａｒｏｓｅ ４Ｂ染料亲和吸附剂,并用来与牛血甭白蛋白（ＢＳＡ）作用,每毫升ＫＧＭ亲和吸附剂可吸附ＢＳＡ ２８ｍｇ,用ＮａＳＣＮ洗脱时间为８４．５％,而Ｓｅｐｈａｒｏｓｅ ４Ｂ染料样和吸附剂每毫升可吸附ＢＳＡ １５．３ｍｇ,用ＮａＳＣＮ洗脱时间收迷８１．７％,并对两种凝胶的染     

Preparation and characterization of konjac glucomannan/poly(diallydimethylammonium chloride) antibacterial blend films

A novel antibacterial film was prepared by blending konjac glucomannan (KGM) and poly(diallydimethylammonium chloride) (PDADMAC) in an aqueous system. The antibacterial activity of the films against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Saccharomyces were measured by the halo zone test and the double plate method. The films exhibited an excellent antibacterial activity against B. subtilis and S. aureus but not against E. coli, P. aeruginosa or Saccharomyces. The miscibility, morphology, thermal stability, water vapour permeability and mechanical properties of the blend films were investigated by density determination, SEM, ATR-IR, XRD, DSC, TGA, WVA and tensile tests. The results of density determination predicted that the blends of KGM and PDADMAC were miscible when the PDADMAC content was less than 70 wt%. Moreover, SEM and XRD confirmed the result. ATR-IR showed that strong intermolecular hydrogen bonds and electrostatic interactions occurred between KGM and PDADMAC in the blends. The tensile strength and the break elongation of the blends were improved largely to 106.5 MPa and 32.04% and the water vapour permeability decreased when the PDADMAC content was 20 wt%. The thermal stability of the blends was higher than pure KGM. The blends should be good antibacterial materials.     

以魔芋葡甘聚糖凝胶为载体亲和层析分离纯化猪血SOD

以魔芋葡甘聚糖（ＫＧＭ）凝胶作为铜金属螯合亲和层析的载体一步亲和纯化猪血ＳＯＤ,得到电泳均一,比活为８６２２Ｕ／ｍｇ,纯化倍数为７７．８倍的ＳＯＤ,其回收率为８５．４％．探讨了魔芋葡甘聚糖凝胶作为亲和载体的可能性及前景．     

The PPFLMLLKGSTR motif in globular domain 3 of the human laminin-5 alpha3 chain is crucial for integrin alpha3beta1 binding and cell adhesion

Laminin-5 regulates various cellular functions, including cell adhesion, spreading, and motility. Here, we expressed the five human laminin alpha3 chain globular (LG) domains as monomeric, soluble fusion proteins, and examined their biological functions and signaling. Recombinant LG3 (rLG3) protein, unlike rLG1, rLG2, rLG4, and rLG5, played roles in cell adhesion, spreading, and integrin alpha3beta1 binding. More significantly, we identified a novel motif (PPFLMLLKGSTR) in the LG3 domain that is crucial for these responses. Studies with the synthetic peptides delineated the PPFLMLLKGSTR peptide within LG3 domain as a major site for both integrin alpha3beta1 binding and cell adhesion. Substitution mutation experiments suggest that the Arg residue is important for these activities. rLG3 protein- and PPFLMLLKGSTR peptide-induced keratinocyte adhesion triggered cell signaling through FAK phosphorylation at tyrosine-397 and -577. To our knowledge, this is the first report demonstrating that the PPFLMLLKGSTR peptide within the LG3 domain is a novel motif that is capable of supporting integrin alpha3beta1-dependent cell adhesion and spreading.     

魔芋葡甘聚糖在固定化领域里的应用

魔芋葡甘聚糖是天然中性多糖,具有良好的成膜、增稠、共混、定型、凝胶和生物相容性等性能,在农业、环境、医药卫生、生物等领域有广泛的应用。鉴于KGM的上述特性以及如今对环保型材料的热点研究,文章总结了KGM作为固定化材料在固定化领域里的应用。另外,就固定化载体的特点及较常见的载体材料、KGM的物理、化学的改性方法等作了简述。近年来,众多研究者已经在载体不溶性的处理、活化、改性、制备KGM微胶囊方面作了许多研究,今后可以注重发掘KGM在精细化工、生物材料等方面的突破点,扩大KGM的应用范围。     

魔竽葡苷聚糖凝胶为亲和层析载体与Sepharose 4B的比较研究——Ⅰ.KGM金属螯和层析分离纯化猪血SOD

将KGM凝胶和Sepharose 4B在同样条件下活化偶联,制成Cu~(2 )金属螫合亲和胶,亲和纯化猪血SOD,并对这两种亲和胶的层析效果和性能进行了比较。KGM金属螫合胶对猪血SOD吸附量、纯化倍数、纯化SOD的比活力和回收率分别为53000U/ml胶、19倍、12000U/mg蛋白和94.6％,而Sepharose 4B亲和胶对SOD 的吸附量、纯化倍数、纯化SOD的比活力和回收率分别为79920U/ml胶、11倍、10125U/mg蛋白和95.4％。两种亲和胶所纯化的SOD经聚丙烯酰胺凝胶电泳(PAGE)、活性染色及SDS聚丙烯酰胺凝胶电泳(SDS-PAGE)证明其均为电泳纯。KGM金属螯合胶使用六次后,其对SOD吸附量、去Cu量及SOD的回收率均无明显影响。     

魔芋葡甘露聚糖固定化环糊精葡基转移酶的研究

本文报道将魔芋葡甘露聚糖(简称KGM),经不溶性处理和一定的化学修饰活化作固定化载体,用共价键合法固定化环糊精葡基转移酶(简称CGTase)。其中,用表氯醇-已二胺-戊二醛修饰活化的KGM载体固定化CGTase效果最好,偶联蛋白质多在20mg/g载体以上,酶活500～900u/g载体之间,最高可超过52mg/g和1300u/g载体。固定化CGTase在pH5和pH10呈两个酶活峰值,最适温度60℃。以淀粉为底物批式连续反应,转化率均在90％以上。