STUDY ON THE MODE OF ACTION OF MONOCLONAL NONSPECIFIC SUPPRESSOR FACTOR (MNSF)

用抗单克隆抗体纯化杂交瘤衍生的单克隆非特异性抑制因子（MNSF）。在还原条件下对纯化的天然MNSF进行SDS-聚丙烯酰胺凝胶电泳，然后进行免疫印迹转移和氨基黑化学染色。切下70-kDa条带，并进行氨基酸序列分析。测定了N端18个氨基酸的序列。合成了5个氨基酸的简并引物，并用于RF-PCR。MNSF α mRNA在伴刀豆球蛋白A（Con A）激活（12小时）的T细胞中表达，但在未刺激的T细胞中不表达。从部分MNSF α cDNA推导的氨基酸序列显示与任何已知蛋白质没有同源性。然而，该序列显示与T细胞受体（TCR）α链有35%的同源性，具有良好的聚集性，假设MNSF α可能与TCR α链相关。全MNSF α cDNA的测序正在进行中。在不久的将来，使用重组MNSF α阐明MNSF的作用方式应该是可能的。

Hybridoma-derived monoclonal nonspecific suppressor factor (MNSF) was purified with the use of anti-MNSF monoclonal antibody. SDS-polyacryl amide gel electrophoresis of the purified native MNSF was performed under reducing conditions, followed by immunoblot transfer and chemical staining with Amino black. The 70-kDa band was excised, and subjected to amino acid sequence analysis. The N-terminal sequence of 18 amino acids was determined. Degenerated primers corresponding to five amino acids were synthesized and used for RF-PCR.MNSFalpha mRNA was expressed in concanavalin A (Con A) activated (12 hours ) -, but not in unstimulated- T cells. The amino acid sequences deduced from the partial MNSFalpha cDNA showed no homology to any known proteins. However, the sequence showed 35% homology to T cell receptor (TCR) alpha chain in good aggrement with a hypothesis that MNSFalpha might be related to TCRalpha chain. The sequencing of full MNSFalpha cDNA was under way. The elucidation of the mode of action of MNSF with the use of recombinant MNSFalpha should be possible, in the near future.