论文部分内容阅读
目的对B糖基转移酶R168W突变导致B_(el)亚型的分子机制进行研究。方法免疫血清学、ABO基因型SSP-PCR检测及直接测序患者及其家系成员ABO基因第6、第7外显子测序。构建3D分子模型,并就GTB蛋白突变对结构影响进行预测。结果经吸收放散试验在患者红细胞上检出弱B抗原,血清中未检测到抗-A、检出抗-B;患者女儿血清学结果呈正常B型。SSP-PCR结果证实患者及其女儿ABO血型基因型为O1/B和B/B型。对ABO基因第6、第7外显子测序,患者及其女儿带有c.502C>T突变,即B_(el)03等位基因,导致氨基酸置换R168W。分子模建与分析提示突变可能降低了蛋白结构的稳定性,影响了B转移酶的总体活性。结论 ABO基因c.502C>T突变通过减低GTB的稳定性导致患者出现B_(el)表型。
OBJECTIVE: To study the molecular mechanism of the B el subtype by mutation of the R glycosyltransferase R168W. Methods Immunohistochemistry, ABO genotype SSP-PCR detection and direct sequencing of patients and their family members ABO gene 6, 7 exon sequencing. The 3D molecular model was constructed and the structural effects of GTB protein mutations were predicted. Results Absorption and desorption tests revealed weak B antigen on erythrocytes in patients, anti-A was not detected in serum and anti-B was detected. Serum B was positive in daughter of patient. The results of SSP-PCR confirmed that the ABO blood group genotypes of patients and their daughters were O1 / B and B / B. Sequencing of exons 6 and 7 of the ABO gene was performed in patients and their daughters with the c.502C> T mutation, the B el 03 gene, resulting in the amino acid substitution R168W. Molecular modeling and analysis suggest that mutations may reduce the stability of the protein structure, affecting the overall activity of B transferase. Conclusions The c.502C> T mutation of ABO gene leads to B el phenotype in patients by reducing the stability of GTB.