Haptoglobin (Hp) is a plasma glycoprotein that scavenges cell‐free hemoglobin (Hb). Hp has various potential therapeutic applications, but it has been mainly studied for treatment of acute hemolytic conditions that can arise from situations such as massive blood transfusion, infusion of stored red blood cells, severe burns, trauma, sepsis, radiation injury, and others. Therefore, Hp may also be beneficial during chronic hemolytic disease states such as hereditary spherocytosis, nocturnal hemoglobinuria, sickle‐cell anemia, and malaria. Various methods have been developed to purify Hp from plasma or plasma fractions. However, none of these methods have exploited the large molecular weight (MW) range distribution of Hp polymers to easily isolate Hp from other plasma proteins. The present study used tangential flow filtration (TFF) to isolate polymeric Hp from plasma proteins using human Fraction IV (FIV) as the starting material. After removal of insoluble material from a suspension of FIV paste, the protein mixture was clarified on a 0.2 μm hollow fiber (HF) TFF filter. The clarified protein solution was then bracketed based on protein MW using HF filters with MW cut‐offs (MWCOs) of 750, 500, and 100 kDa. Using untreated FIV, the Hp purity of the main bracket was ~75% with a total Hb binding capacity (HbBC) yield of 1.2 g starting from 500 g of FIV paste. However, pretreatment of FIV with fumed silica to remove lipoproteins increased Hp purity to >95% with a HbBC yield of 1.7 g per 500 g of FIV. Taken together this study provides a novel and scalable method to purify Hp from plasma or plasma fractions.

中文翻译：

---

触珠蛋白的切向流过滤。

触珠蛋白 (Hp) 是一种血浆糖蛋白，可清除无细胞血红蛋白 (Hb)。Hp 具有多种潜在的治疗应用，但主要用于治疗急性溶血病，这些病况可能由大量输血、输注储存的红细胞、严重烧伤、外伤、败血症、放射损伤等情况引起。因此，Hp 也可能有益于慢性溶血性疾病，如遗传性球形红细胞增多症、夜间血红蛋白尿、镰状细胞性贫血和疟疾。已经开发了多种方法来从血浆或血浆组分中纯化 Hp。然而，这些方法都没有利用 Hp 聚合物的大分子量 (MW) 范围分布来轻松地将 Hp 与其他血浆蛋白分离。本研究使用切向流过滤 (TFF) 从血浆蛋白中分离聚合 Hp，使用人组分 IV (FIV) 作为起始材料。从 FIV 糊状物的悬浮液中去除不溶性物质后，在 0.2 μm 中空纤维 (HF) TFF 过滤器上澄清蛋白质混合物。然后使用具有 750、500 和 100 kDa 的 MW 截止值 (MWCO) 的 HF 过滤器根据蛋白质 MW 将澄清的蛋白质溶液括起来。使用未经处理的 FIV，主支架的 Hp 纯度为~75%，从 500 g FIV 糊剂开始，总 Hb 结合能力 (HbBC) 产量为 1.2 g。然而，用气相二氧化硅预处理 FIV 以去除脂蛋白将 Hp 纯度提高到 >95%，每 500 g FIV 的 HbBC 产量为 1.7 g。总之，这项研究提供了一种从血浆或血浆组分中纯化 Hp 的新颖且可扩展的方法。