磁化率能够衡量磁珠向磁力架迁移的速度,其大小取决于铁含量和氧化铁的特性。Dynabeads磁珠的磁化率是指质量磁化率,单位可以是cgs单位/g或m^3/kg(国际单位制)。对于亚铁磁性和铁磁性物质,质量磁化率取决于磁场强度(H),这些物质的磁化强度与H不是线性关系,而是随着场强增加而趋于饱和。因此, Dynabeads磁珠的质量磁化率是在固定条件下由标准操作程序而测定的。我们产品目录中给出的质量磁化率是国际单位制。磁化率由从高斯(cgs、emu)单位向国际单位的转换,是通过“高斯系数(emu/g或cgs/g)x 4π x 10^-3”而实现的。所得单位也被称为合理化质量磁化率,与(国际单位制)无量纲磁化率单位有所区别。通常,质量磁化率可用来衡量在非均匀磁场中影响物体的力(Fz)。测定Dynabeads磁珠的质量磁化率时,首先对样本称重,然后将样本放置于已知强度的磁场中。随后,再次称重得到样本重量(F1),并与关闭磁场时样本的重量(F0)进行对比。使用下述公式计算磁化率:K x 10^–3 = [(F1-F0) x m x 0.335 x 10^6],K表示质量为m的样本的质量磁化率。最后,将磁化率转换为国际单位制。
The heme activator protein Hap1 represses transcription by a heme-independent mechanism in Saccharomyces cerevisiae.
Authors:Hon T, Lee HC, Hu Z, Iyer VR, Zhang L,
Journal:Genetics
PubMed ID:15654089
The yeast heme activator protein Hap1 binds to DNA and activates transcription of genes encoding functions required for respiration and for controlling oxidative damage, in response to heme. Hap1 contains a DNA-binding domain with a C6 zinc cluster motif, a coiled-coil dimerization element, typical of the members of the yeast ... More
The luminal Vps10p domain of sortilin plays the predominant role in targeting to insulin-responsive Glut4-containing vesicles.
Authors:Shi J, Kandror KV,
Journal:J Biol Chem
PubMed ID:17220298
In fat and skeletal muscle cells, insulin-responsive vesicles, or IRVs, deliver glucose transporter Glut4 and several associated proteins to the plasma membrane in response to hormonal stimulation. Although the protein composition of the IRVs is well studied, the mechanism of their formation is unknown. It is believed, however, that the ... More