Mamrack M D
Wright State University, Dayton, Ohio 45435.
Mol Cell Biochem. 1989 Feb 21;85(2):147-57. doi: 10.1007/BF00577110.
Casein kinase II (CKII) has been purified from bovine heart tissue. Under conditions of low salt (0.05 M NaCl, 10 mM MgCl2), CKII forms structured aggregates that appear as filaments similar to results obtained with Drosophila CKII [C.V.C. Glover (1986) J. Biol. Chem. 261:14349]. The aggregates have been analyzed by sucrose density gradients and electron microscopy. Filament preparations of the enzyme have reduced but measurable kinase activity. The addition of salt restores activity. Various modulators of CKII activity have been examined with the enzyme in the low salt, polymerized form. The polyamines spermine or spermidine stimulated CKII activity as much as six fold; putrescine had no effect. Polylysine of varying lengths activated CKII 4-6 fold. Melittin, the basic polypeptide from bee venom, was also an effective activator. Activation of filament preparations was also observed if the CKII specific peptide (RRREEETEEE) was used as the substrate in place of casein. These results with filament preparations provide an alternative in vitro system for the study of possible regulatory aspects of CKII.
酪蛋白激酶II（CKII）已从牛心脏组织中纯化出来。在低盐（0.05 M NaCl，10 mM MgCl2）条件下，CKII形成结构化聚集体，呈现出丝状，这与用果蝇CKII获得的结果相似[C.V.C. 格洛弗（1986年）《生物化学杂志》261:14349]。这些聚集体已通过蔗糖密度梯度和电子显微镜进行分析。该酶的丝状制剂的激酶活性有所降低，但仍可测量。添加盐可恢复活性。已在低盐、聚合形式的酶中检测了各种CKII活性调节剂。多胺精胺或亚精胺可将CKII活性刺激多达六倍；腐胺没有作用。不同长度的聚赖氨酸可使CKII活性激活4至6倍。蜂毒中的碱性多肽蜂毒素也是一种有效的激活剂。如果使用CKII特异性肽（RRREEETEEE）代替酪蛋白作为底物，也可观察到丝状制剂的激活。丝状制剂的这些结果为研究CKII可能的调节方面提供了一种体外替代系统。
