Antithrombin Resistance Rescues Clotting Defect of Homozygous Prothrombin-Y510N Dysprothrombinemia.
Antithrombin Resistance Rescues Clotting Defect of Homozygous Prothrombin-Y510N Dysprothrombinemia.
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抗凝血酶抵抗可挽救纯合子凝血酶原-Y510N 凝血酶原异常血症的凝血缺陷
DOI：
10.1055/a-1549-6407
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发表时间：
2022-05
影响因子：
6.7
通讯作者：
Rezaie AR
中科院分区：
文献类型：
--
作者：
Lu Y;Villoutreix BO;Biswas I;Ding Q;Wang X;Rezaie AR
我们门诊有一位血尿的病人被诊断为泌尿系结石。对患者血浆凝血时间的分析表明，APTT（52.6 s）和PT（19.4 s）均延长，凝血酶原活性降低至正常值的12.4%，但患者未表现出异常出血表型，凝血酶原抗原水平为87.9%。基因分析显示患者为凝血酶原Y510 N突变纯合子。我们在适当的凝血试验中表达并表征了凝血酶原-Y510 N变体，发现Xa因子激活突变酶原的特异性常数受损约5倍。使用患者血浆和补充有野生型或凝血酶原-Y510 N的凝血酶原缺陷血浆的凝血酶生成测定揭示，凝血酶原突变体的峰高和达峰时间均降低，然而内源性凝血酶生成潜力增加。进一步的分析表明，凝血酶突变体表现出抗凝血酶和抑制丝氨酸蛋白酶抑制剂的速率常数慢约12倍。凝血酶-Y510 N对蛋白C的激活也降低了约10倍，然而，血栓调节蛋白克服了催化缺陷。的Na+浓度依赖性的酰胺分解活性表明，Na+与突变体的相互作用的解离常数已升高~20倍。这些结果表明，Y510（胰凝乳蛋白酶编号为Y184 a）属于参与结合Na+的残基网络。凝血酶-Y510 N的正常蛋白C活化表明血栓调节蛋白调节凝血酶的Na+结合环的构象。凝血酶-Y510 N的凝血缺陷似乎通过其与抗凝血酶的显著较低反应性来补偿，解释了患者的正常止血表型。
A patient with hematuria in our clinic was diagnosed with urolithiasis. Analysis of the patient’s plasma clotting-time indicated that both APTT (52.6 s) and PT (19.4 s) are prolonged and prothrombin activity is reduced to 12.4% of normal, though the patient exhibited no abnormal bleeding phenotype and a prothrombin antigen level of 87.9%. Genetic analysis revealed the patient is homozygous for prothrombin Y510N mutation. We expressed and characterized the prothrombin-Y510N variant in appropriate coagulation assays and found that the specificity constant for activation of the mutant zymogen by factor Xa is impaired ~5-fold. Thrombin generation assay using patient’s plasma and prothrombin-deficient plasma supplemented with either wild-type or prothrombin-Y510N revealed that both peak height and time to peak for the prothrombin mutant are decreased however the endogenous thrombin generation potential is increased. Further analysis indicated that the thrombin mutant exhibits resistance to antithrombin and is inhibited by the serpin with ~12-fold slower rate constant. Protein C activation by thrombin-Y510N was also decreased ~10-fold, however, thrombomodulin overcame the catalytic defect. The Na+-concentration-dependence of the amidolytic activities revealed that the dissociation constant for the interaction of Na+ with the mutant has been elevated ~20-fold. These results suggest that Y510 (Y184a in chymotrypsin numbering) belongs to network of residues involved in binding Na+. A normal protein C activation by thrombin-Y510N suggests that thrombomodulin modulates the conformation of the Na+-binding loop of thrombin. The clotting defect of thrombin-Y510N appears to be compensated by its markedly lower reactivity with antithrombin, explaining patient’s normal hemostatic phenotype.
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影响因子：
14.9
作者：
Kuriata A;Gierut AM;Oleniecki T;Ciemny MP;Kolinski A;Kurcinski M;Kmiecik S
通讯作者：
Kmiecik S
影响因子：
2.9
作者：
Qureshi, Shabir H.;Yang, Likui;Manithody, Chandrashekhara;Iakhiaev, Alexei V.;Rezaie, Alireza R.
通讯作者：
Rezaie, Alireza R.
影响因子：
14.9
作者：
Burley SK;Bhikadiya C;Bi C;Bittrich S;Chen L;Crichlow GV;Christie CH;Dalenberg K;Di Costanzo L;Duarte JM;Dutta S;Feng Z;Ganesan S;Goodsell DS;Ghosh S;Green RK;Guranović V;Guzenko D;Hudson BP;Lawson CL;Liang Y;Lowe R;Namkoong H;Peisach E;Persikova I;Randle C;Rose A;Rose Y;Sali A;Segura J;Sekharan M;Shao C;Tao YP;Voigt M;Westbrook JD;Young JY;Zardecki C;Zhuravleva M
通讯作者：
Zhuravleva M
影响因子：
5.7
作者：
Huntington, JA;Esmon, CT
通讯作者：
Esmon, CT
影响因子：
20.3
作者：
Akhavan, S;De Cristofaro, R;Mannucci, PM
通讯作者：
Mannucci, PM