Collen D, Sinnaeve P, Demarsin E, Moreau H, De Maeyer M, Jespers L, Laroche Y, Van de Werf F
Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology, KU Leuven, Belgium
Circulation. 2000 Oct 10;102(15):1766-72. doi: 10.1161/01.cir.102.15.1766.
Thrombolytic therapy of acute myocardial infarction (AMI) is evolving toward bolus administration. Derivatization of proteins with polyethylene glycol (PEG) may reduce their clearance.
A staphylokinase (SakSTAR) variant with 12 amino acid substitutions to reduce its antigenicity, SakSTAR (K35A, E65Q, K74R, E80A, D82A, T90A, E99D, T101S, E108A, K109A, K130T, K135R), and with Ser in position 3 mutated into Cys (code SY161), was derivatized with maleimide-PEG with M:(r) of 5,000 (P5), 10,000 (P10), or 20,000 (P20). The PEGylated variants recognized only one third of the antibodies elicited with wild-type SakSTAR in AMI patients. In experimental animals, plasma clearances were reduced 2. 5- to 5-fold with P5, 5- to 20-fold with P10, and 20-fold with P20, and bolus injection induced pulmonary plasma clot lysis at doses inversely related to their clearance. Intravenous bolus injection of 5 mg of the P5, P10, or P20 variants in AMI patients was associated with plasma half-lives (t(1/2alpha)) of 13, 30, and 120 minutes and clearances of 75, 43, and 8 mL/min, respectively, compared with 3 minutes and 360 mL/min for SakSTAR. Injection of 5 mg P5 variant restored TIMI-3 flow within 60 minutes in 14 of 18 AMI patients (78%, 95% CI 55% to 91%) and of 2.5 mg in 7 of 11 patients (63%, 95% CI 35% to 85%), both in the absence of fibrinogen degradation. The immunogenicity of the variants was significantly (P:<0.002) reduced.
The staphylokinase variant SY161-P5, derivatized with one linear polyethylene glycol molecule of M:(r) 5000, is a promising fibrin-selective agent for single-bolus coronary thrombolysis.
急性心肌梗死（AMI）的溶栓治疗正朝着大剂量给药方向发展。用聚乙二醇（PEG）对蛋白质进行衍生化修饰可能会降低其清除率。
一种具有12个氨基酸取代以降低其抗原性的葡萄球菌激酶（SakSTAR）变体，即SakSTAR（K35A、E65Q、K74R、E80A、D82A、T90A、E99D、T101S、E108A、K109A、K130T、K135R），且其3位的丝氨酸突变为半胱氨酸（编码SY161），用分子量为5000（P5）、10000（P10）或20000（P20）的马来酰亚胺 - PEG进行衍生化修饰。聚乙二醇化变体仅能识别AMI患者中由野生型SakSTAR引发抗体的三分之一。在实验动物中，P5使血浆清除率降低2.5至5倍，P10使其降低5至20倍，P20使其降低20倍，大剂量注射时诱导肺血浆凝块溶解的剂量与其清除率呈反比。在AMI患者中静脉大剂量注射5mg的P5、P10或P20变体，其血浆半衰期（t(1/2α)）分别为13、30和120分钟，清除率分别为75、43和8 mL/min，而SakSTAR的血浆半衰期为3分钟，清除率为360 mL/min。注射5mg P5变体后，18例AMI患者中有14例（78%，95%可信区间55%至91%）在60分钟内恢复TIMI - 3级血流，注射2.5mg时，11例患者中有7例（63%，95%可信区间35%至85%）恢复TIMI - 3级血流，且均未出现纤维蛋白原降解。变体的免疫原性显著降低（P<0.002）。
用一个分子量为5000的线性聚乙二醇分子衍生化修饰的葡萄球菌激酶变体SY161 - P5，是一种有前景的用于单次大剂量冠状动脉溶栓的纤维蛋白选择性药物。
