Initiative Project of Translational Medicine, Shandong Academy of Medical Sciences, Jinan 250062, China.
Peptides. 2012 Jan;33(1):170-3. doi: 10.1016/j.peptides.2011.11.021. Epub 2011 Dec 2.
Hemorphins are a set of hemoglobin-derived opioid peptides. The production mechanism of these structural overlap peptides remains unclear. Based on the sequences of hemorphins, it could be inferred that hemorphins are probably generated by cleavage of hemoglobin β chain at sites favored by the chymotrypsin-like protease. 20S proteasome possesses the chymotrypsin-like activity and still persists in mature erythrocytes. This study attempts to clarify whether the intraerythrocytic proteasome involves in the formation of hemorphins. Hemorphins containing hemorphin-7 and V-hemorphin-7 are isolated by immunoprecipitation from culture supernatant of human erythrocytes. Bortezomib inhibits the chymotrypsin-like activity of intraerythrocytic proteasome and prevents the yield of hemorphins in a dose-dependent manner. The present study suggests that intraerythrocytic proteasome contributes to the generation of hemorphins.
血红蛋白衍生的阿片样肽是一组血红蛋白衍生的阿片样肽。这些结构重叠肽的产生机制尚不清楚。根据血红蛋白的序列，可以推断血红蛋白可能是由糜蛋白酶样蛋白酶偏好的位点切割血红蛋白β链产生的。20S 蛋白酶体具有糜蛋白酶样活性，并且仍然存在于成熟的红细胞中。本研究试图阐明细胞内蛋白酶体是否参与了血红蛋白的形成。从人红细胞培养上清液中通过免疫沉淀分离含有血红蛋白-7 和 V-血红蛋白-7 的血红蛋白。硼替佐米抑制细胞内蛋白酶体的糜蛋白酶样活性，并以剂量依赖性方式阻止血红蛋白的产生。本研究表明，细胞内蛋白酶体有助于血红蛋白的生成。
