Walton G M, Spiess J, Gill G N
J Biol Chem. 1985 Apr 25;260(8):4745-50.
Phosphorylation of chromosomal high mobility group (HMG) protein 14 by casein kinase II has been characterized. Two mol of 32P are incorporated per mol of bovine HMG 14. Kinetic analysis provided evidence for two distinct sites with apparent Km values of 14.5 and 134 microM and respective Vmax values of 0.17 and 0.68 mumol/min/mg casein kinase II. Tryptic peptide mapping identified two phosphorylated products, each with phosphoserine. Amino acid composition and sequence analysis demonstrate that the major high affinity phosphorylation site for casein kinase II is serine 89. This sequence located at the carboxyl-terminal of HMG 14 contains the primary sequence determinants for casein kinase II. On the basis of reverse-phase high performance liquid chromatography and amino acid analysis, HMG 14, serine 99 represents the low affinity phosphorylation site.
酪蛋白激酶II对染色体高迁移率族（HMG）蛋白14的磷酸化作用已得到表征。每摩尔牛HMG 14掺入两摩尔32P。动力学分析为两个不同的位点提供了证据，其表观Km值分别为14.5和134 microM，酪蛋白激酶II的各自Vmax值分别为0.17和0.68微摩尔/分钟/毫克。胰蛋白酶肽图谱分析鉴定出两种磷酸化产物，每种都含有磷酸丝氨酸。氨基酸组成和序列分析表明，酪蛋白激酶II的主要高亲和力磷酸化位点是丝氨酸89。该序列位于HMG 14的羧基末端，包含酪蛋白激酶II的主要序列决定因素。基于反相高效液相色谱和氨基酸分析，HMG 14的丝氨酸99代表低亲和力磷酸化位点。
