KINETIC PROPERTIES OF MUTANT HOLOCARBOXYLASE SYNTHETASES

突变型全羧化酶合成酶的动力学特性

• 批准号: 10470172
• 负责人: NARISAWA Kuniaki
• 金额: $ 8.26万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10470172/
• 关键词: BIOTIN; HOLOCARBOXYLASE SYNTHETASE DEFICIENCY; MUTATION; KINETICO; MULTIPLE CARBOXYLASE DEFICIENCY; Vmax値; 開始コドン; ペプチド抗体; ウエスタンブロット; ピオチン反応性

Holocarboxylase synthetase (HCS) deficiency is a metabolic disorder causing a biotin-responsive multiple carboxylase deficiency. We analyzed the kinetic property of several mutant HCS proteins. Two mutants located within the putative biotin-binding site of HCS showed elevated Km values for biotin compared to those of the wild-type form. On the other hand, the remaining five mutations were outside of the biotin-binding site. The enzymes containing these mutations showed normal or low Km values for biotin (non-Km mutant). Symptoms of patients who have the non-Km mutants, as well as those of patients who have the Km mutants, responded to biotin therapy. The responsiveness to biotin supplement of propionyl-CoA carboxylase activity in cultured cells bearing some of these mutations correlated well to the corresponding reduction in the Vmax. Patients who have mutant HCS proteins with lower Vmax showed poor clinical and biochemical responses to biotin therapy. The determination of HCS genotype can be valuable for characterizing the clinical phenotype in HCS deficient patients.

全羧化酶合成酶（HCS）缺乏症是一种引起生物素反应性多种羧化酶缺乏症的代谢紊乱。我们分析了几种突变HCS蛋白的动力学特性。位于HCS的假定生物素结合位点内的两个突变体显示与野生型形式相比生物素的Km值升高。另一方面，其余5个突变在生物素结合位点之外。含有这些突变的酶对生物素显示正常或低Km值（非Km突变体）。具有非Km突变体的患者的症状以及具有Km突变体的患者的症状对生物素治疗有反应。对生物素补充的丙酰辅酶A羧化酶活性在培养的细胞轴承这些突变中的一些相关性以及相应的减少Vmax。具有较低Vmax的突变HCS蛋白的患者对生物素治疗显示出较差的临床和生化应答。HCS基因型的测定对HCS缺陷患者的临床表型特征有价值。

项目成果

M.Hiratsuka,et al.: "Identification of holocarboxylase synthetase proteins in human placenta" Biochemica Biophysica Acta. 1385. 165-171 (1998)

M.Hiratsuka 等人：“人胎盘中全羧化酶合成酶蛋白的鉴定”《生物化学生物物理学学报》。

Y.Nagasaki,et al.: "Reversal of hypopigmentation in PKU model mice by gene transfer" Pediatric Research. 45(in press). (1999)

Y.Nagasaki 等人：“通过基因转移逆转 PKU 模型小鼠色素沉着不足”儿科研究。

Fujii K.et al.: "Mutation detection by TaqMan-allele specific amplification : Application to molecular diagnosis of glycogen storage disease type Ia and medium-chain acyl-CoA dehydrogenase deficiency"Human Mutation. 15,2. 189-196 (2000)

Fujii K.等人：“通过 TaqMan 等位基因特异性扩增进行突变检测：应用于 Ia 型糖原贮积病和中链酰基辅酶 A 脱氢酶缺乏症的分子诊断”人类突变。

Aoki, Y, et al.: "Identification and characterization of mutations in patients with holocarboxylase synthetase deficiency"Human Genetics. 104,2. 143-148 (1999)

Aoki, Y 等人：“全羧化酶合成酶缺乏症患者突变的鉴定和表征”人类遗传学。

Hou D.et al.: "Glycogen storage disease type Ib : structural and mutation analysis of the microsomal glucose-6-phosphate transporter gene"American Journal of Human Genetics. 86,3. 254-257 (1999)

侯D.等人：“Ib型糖原贮积病：微粒体葡萄糖-6-磷酸转运蛋白基因的结构和突变分析”美国人类遗传学杂志。