Studies on human complement 4 binding protein

1.人C4-结合蛋白（C4 BP）的纯化和抗纯化C4 BP抗体的开发通过多个步骤从1.5L血浆中纯化人C4 BPalpha，所述多个步骤包括BaCl 2沉淀、内毒素吸附、超离心、乙醇/乙醚萃取、柱色谱（DE 52、S400和S300）。针对这种蛋白质的抗体在兔子和小鼠中产生。还开发了单克隆抗体（IgG）。2.人基因组C4 BP基因分析人基因组C4 BPalpha基因。该基因由12个外显子组成，跨度约40 kb。每个SCR由单个外显子编码，除了第二个SCR（SCR II），其由两个单独的外显子编码。对5'侧翼区进行测序，从推定的转录起始位点上游至380个碱基。几个可能的结合位点的转录因子进行了鉴定。3. C4 BP α的基因表达证实了C4 BP α在正常肝细胞和肝癌细胞系中的基因表达。C4 BPalpha的肝癌细胞系，HepG 2的组成型基因表达，显着增强治疗与单核细胞条件培养基，12-O-十四烷酰佛波醇-13-乙酸酯，白细胞介素-6和肿瘤坏死因子，但不是由钙离子载体或白细胞介素-1 β。4.血清C4 BP水平测定各种自身免疫性疾病患者血清C4 BP水平。活动性或LAC阳性的SLE、Behcet病、前列腺炎、PSS、RA和MCTD患者C4 BP水平显著升高。C4 BP水平与CRP、C3、CH 50相关。

1. Purification of human C4-binding protein (C4BP) and development of antibody against the purified C4BP Human C4BPalpha was purified from 1.5L of plasma by multiple steps including BaC12 precipitation, Intralipid absorption, ultracentrifugation, ethanol/ethel extraction, column chromatographies (DE52,S400 and S300). Antibodies against this protein were raised in rabbits and mice. Monoclonal antibody (IgG) was also developed. 2. Human genomic C4BP gene Human genomic C4BPalpha gene was analyzed. This gene consists of 12 exons and spans about 40 kb. Each of the SCRs is encoded by a single exon, except for the second SCR (SCR II), which is encoded by two separate exons. The 5' flanking region was sequenced up to 380 bases upstream from the putative transcription initiation site. Several possible binding sites for transcription factors were identified. 3. Gene expression of the C4BPalpha The gene expression of the C4BP alpha in normal liver cell and hepatoma lines was demonstrated. The constitutive gene expression of C4BPalpha by a hepatoma line, HepG2, was significantly augmented by treatment with monocyte conditioned medium, 12-O-tetradecanoylphorbol-13-acetate,interleukin-6 and tumor necrosis factor but not by a calcium ionophore or interleukin-1beta. 4. Serum levels of C4BP Serum levels of C4BP were measured in patients with various autoimmune disease. Significantly high level of C4BP was observed in patients with active or LAC-positive SLE,Behcet disease, aortitis, PSS,RA and MCTD. The level of C4BP was correlated with CRP, C3 and CH50.