人类带3蛋白胞质片段的表达纯化及其性质表征

带3蛋白胞质片段(cdb3)具有多种生理功能：它可以将膜和膜骨架蛋白相联，起着维持细胞形状以及沟通内外环境的作用。而且，它还通过与多个糖酵解酶的相互作用来调节红细胞内糖酵解速率。它的这些功能很大程度上归因于它的分子柔性大，可以通过各种构象与膜蛋白、糖酵解酶等竞争性结合。 在本文中，我们首先运用分子克隆技术在大肠杆菌BL21(DE3)中成功地构建pET28b-cdb3表达体系。经37℃培养至OD600达0.6时，加入1mM IPTG ，于30℃诱导表达cdb3蛋白。经离子交换和亲和层析两步纯化得到电泳纯的具有生物活性的cdb3蛋白。之后，我们首次较为系统地表征了cdb3蛋白的构象特点：在常规的生理环境下, cdb3蛋白呈现典型的α-螺旋、β折叠二级结构， cdb3的四个Trp残基很大程度地包埋于疏水环境中；随溶液GuHCl浓度增加，cdb3 的四个Trp残基逐渐暴露于极性环境中；当pH值从6.0升高到10.0时，cdb3的Tm值逐渐降低约15℃，其内源荧光强度增加两倍，并在pH 7.2和pH9.2处呈现拐点，而蛋白的二级结构却没有发生变化。金属离子Cd2+、Ca2+、Cu2+、Co2+、Mg2 、Zn2+的结合位点在cdb3蛋白的Trp残基附近，而50μM的金属离子对重组cdb3蛋白的二级结构影响微小。最后，我们合成了cdb3蛋白N端肽段1－23，发现其在水溶液中呈无规卷曲结构，TFE可诱导其形成α螺旋，当TFE浓度增至80%时α螺旋含量达最高。无规卷曲的肽段不与醛缩酶相结合，其以α螺旋形式与醛缩酶相结合。 ATP可与肽段、重组cdb3蛋白结合，并对其光谱学性质有一定影响。当ATP浓度达到3mM时，重组cdb3蛋白发生聚集。

The interaction of aldolase with the cytoplasmic domain of human erythrocyte band 3 inhibited by lanthanum ions

The effect of lanthanum ions on the activity of the cytoplasmic domain of human erythrocyte band 3 (CDB3), which was measured according to the inhibition to aldolase, was studied. In the presence of low concentration of lanthanum ions, the function of CDB3 to inhibit aldolase activity decreased significantly. It indicated that lanthanum ions in the erythrocyte would change the conformation of CDB3 and influence the control on aldolase activity.

Computational simulation methodologies for mechanobiological modelling: a cell-centred approach to neointima development in stents

The design of medical devices could be very much improved if robust tools were available for computational simulation of tissue response to the presence of the implant. Such tools require algorithms to simulate the response of tissues to mechanical and chemical stimuli. Available methodologies include those based on the principle of mechanical homeostasis, those which use continuum models to simulate biological constituents, and the cell-centred approach, which models cells as autonomous agents. In the latter approach, cell behaviour is governed by rules based on the state of the local environment around the cell; and informed by experiment. Tissue growth and differentiation requires simulating many of these cells together. In this paper, the methodology and applications of cell-centred techniques-with particular application to mechanobiology-are reviewed, and a cell-centred model of tissue formation in the lumen of an artery in response to the deployment of a stent is presented. The method is capable of capturing some of the most important aspects of restenosis, including nonlinear lesion growth with time. The approach taken in this paper provides a framework for simulating restenosis; the next step will be to couple it with more patient-specific geometries and quantitative parameter data.