N－羟甲基中卟啉诱导产生抗体的酶学性质研究

Studies on the Enzymological Properties of Antibody Induced by N-hydroxymethylmesohemin

以Ｎ－羟甲基中卟啉为半抗原，通过动物免疫、细胞融合等技术筛选得到的细胞株１１Ｄ~１，该细胞株产生的抗体具有结合铁中卟啉的能力，且表现出过氧化物酶活力。进一步研究表明，该抗体对半抗原及铁中卟啉的亲和力分别为：１．１×１０^（－６）ｍｏｌ／Ｌ和２．１×１０^（－６）ｍｏｌ／Ｌ；抗体－铁中卟啉复合物催化反应时，对底物过氧化氢的Ｋ_ｍ＝１３．０ｍｍｏｌ／Ｌ，Ｋ_（ｃａｔ）＝８６ｍｉｎ^（－１），与自然催化速度相比，活力提高１．８×１０~４（ｍｏｌ／Ｌ）^（－１）。

N-hydroxymethylmesohemin was used as haptin to elicit monoclonal antibody 11D1 through the immunization and cell fusion techniques.The antibody had the ability to combine with mesohemin and showed the activity of peroxidase.Further investigations demonstrate that the affinities of antibody for haptin and mesohemin were 1.1×10(-6)and 2.1×10(-6)mol/L respectively. When antibody-mesohemin complex catalyzed reaction, its Km and K(cat) for H2O2 were 13. 0 mmol/Land 86 min(-1) respectively. Compared with the noncat alyzed reaction, the activity of antibody-mesohemin complex elevated 1.8× 104(mol/L)(-1).