Williamson K C, Keister D B, Muratova O, Kaslow D C
Biology Department, Loyola University, Chicago, IL 60626, USA.
Mol Biochem Parasitol. 1995 Dec;75(1):33-42. doi: 10.1016/0166-6851(95)02507-3.
Six regions of malaria transmission-blocking target antigen, Pfs230, encoding 80% of the 363-kDa protein, were expressed as recombinant proteins in E. coli as fusions with maltose-binding protein (MBP). Antisera generated against amylose-purified recombinant Pfs230/MBP fusion proteins (r230/MBP.A-r230/MBP.F) all recognized the 360-kDa form of parasite-produced Pfs230 by immunoblot. However, only antisera against the four carboxy regions (C-F) of Pfs230 and not the two amino regions (A and B) recognized the 310-kDa form of Pfs230, the form expressed on the surface of gametes. The data suggest that the 310-kDa form of Pfs230 arises from the cleavage of 50 kDa from the amino terminus of the 360-kDa form. Furthermore, antisera against r230/MBP.C bound to the surface of intact gametes and significantly reduced (by 71.2-89.8% (rank sum analysis, P < 0.01)) the infectivity of P. falciparum parasites to mosquitoes. This is the first report of a recombinant form of a P. falciparum gametocyte protein capable of inducing antisera that reduce malaria parasite infectivity to mosquitoes.
疟原虫传播阻断靶抗原Pfs230的六个区域，编码了363 kDa蛋白的80%，在大肠杆菌中作为与麦芽糖结合蛋白（MBP）融合的重组蛋白表达。针对直链淀粉纯化的重组Pfs230/MBP融合蛋白（r230/MBP.A - r230/MBP.F）产生的抗血清，通过免疫印迹均能识别寄生虫产生的360 kDa形式的Pfs230。然而，只有针对Pfs230四个羧基区域（C - F）而非两个氨基区域（A和B）的抗血清，能识别配子表面表达的310 kDa形式的Pfs230。数据表明，310 kDa形式的Pfs230是由360 kDa形式的氨基末端切割掉50 kDa产生的。此外，针对r230/MBP.C的抗血清与完整配子表面结合，并显著降低（通过秩和分析，降低71.2 - 89.8%，P < 0.01）恶性疟原虫对蚊子的感染性。这是关于一种能够诱导产生降低疟原虫对蚊子感染性抗血清的恶性疟原虫配子体蛋白重组形式的首次报道。
