奶牛孕酮酶联免疫检测试剂盒的研制

为了掌握母牛孕酮水平变化信息,为发情鉴定、妊娠鉴别和卵巢疾病诊断提供参考依据,根据EHSA基本原理,研制了奶牛孕酮ELISA检测试剂盒。结果表明,采用孕酮-牛血清白蛋白（P4-BSA）交联物解决了在酶标板上包被抗原的问题,且抗原容易保存;而利用孕酮-卵清白蛋白（P4-OVA）交联物免疫兔子获得高效价抗体,能阻断1ng/mL孕酮水平;并以ELISA棋盘测定法确定P4-BSA 2000倍、血清500倍稀释为该试剂盒最佳工作浓度。该试剂盒以牛粪作为检测样品,即通过粪便中的孕酮水平变化可为奶牛发情鉴定、妊娠鉴别、繁殖障碍性疾病诊断提供可靠的技术支撑。     

鼠源环丙沙星多克隆抗体的制备

为了制备环丙沙星(CPLX)多克隆抗体,将修饰成功的CPLX-NH2分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)偶联,制备完全抗原—CPLX-NH2-BSA和CPLX-NH2-OVA,用CPLX-NH2-BSA免疫小鼠,获得了高效价的环丙沙星多克隆抗体.     

磺胺二甲嘧啶人工抗原的合成与鉴定

采用重氮化法将磺胺二甲嘧啶(Sulfadimidine,SM2)与牛血清白蛋白(Bovine serum albumin,BSA)和卵清蛋白(Ovalbumin,OVA)交联合成人工抗原SM2-BSA与SM2-OVA,并研究了SM2重氮盐的稳定性,以确保偶联反应顺利进行.通过紫外扫描、高效毛细管电泳检测合成效果,用免疫原(SM2-BSA)免疫BALB/c小鼠,检测抗血清.结果表明,SM2-BSA和SM2-OVA均偶联成功.     

伏马菌素B_1人工抗原的鉴定及抗体的制备

采用戊二醛(GA)一步法将半抗原伏马菌素B1(FB1)分别与鸡卵清蛋白(OVA)、牛血清白蛋白(BSA)偶联,制备2种具有免疫原性的FB1人工抗原FB1-OVA和FB1-BSA。分别采用凝胶电泳法、紫外光谱法(UV)、红外光谱法(IR)、基质辅助激光分析电离飞行时间质谱法(MALDI-TOF-MS)4种方法鉴定人工抗原偶联效果并测定偶联比。将FB1-BSA作为免疫抗原免疫BALB/c小鼠,FB1-OVA作为固相包被抗原,采用间接酶联免疫吸附法(i-ELISA)测定小鼠抗血清滴度。结果表明:4种方法均鉴定FB1人工抗原合成成功。凝胶电泳法测定FB1-OVA和FB1-BSA相对分子质量分别约为50 000和75 000。MALDI-TOF-MS测定FB1-OVA和FB1-BSA相对分子质量分别为48 009.212和74 355.301,并精确计算FB1-OVA和FB1-BSA偶联比分别为5∶1和10∶1。FB1-BSA免疫后小鼠的抗血清效价为1∶1.25×105,并具有较高灵敏度。     

硫代磷酸酯类农药通用抗原的合成与鉴定

【目的】合成具有硫代磷酸酯类农药共性结构的系列半抗原,制备此类农药的通用人工抗原。【方法】以烷氧基硫代磷酸盐和卤代羧酸为原料合成半抗原,采用¹HNMR、¹³CNMR及EIS-MS谱图对其结构进行表征。将合成的半抗原分别通过活性酯法、混合酸酐法与牛血清白蛋白（BSA）、卵清蛋白（OVA）偶联,制备免疫人工抗原和包被人工抗原。用紫外扫描法定性分析人工抗原的偶联情况,用2,4,6-三硝基苯磺酸（TNBS）法间接测定其偶联比。【结果】合成了H1～H6 6种具有硫代磷酸酯类农药共性结构的半抗原,其中H1、H2为包被半抗原,H3～H6为免疫半抗原。制备了H1-OVA、H2-OVA、H3-BSA、H4-BSA、H5-BSA、H6-BSA、H2-BSA、H4-OVA和H6-OVA 9种人工抗原,其偶联比分别为9∶1、10∶1、23∶1、26∶1、39∶1、43∶1、28∶1、14∶1和12∶1。【结论】成功合成硫代磷酸酯类农药的人工抗原,为下一步用其免疫动物制备抗体进而进行有机磷农药酶联免疫分析奠定了基础。     

溴虫腈半抗原及全抗原合成与鉴定

以杀虫剂溴虫腈为起始原料,合成了半抗原4-溴-2-(对氯苯基)-1-乙氧基甲基-5-(三氟甲基)吡咯-3-甲胺(简称CFP-NH:).通过戊二醛法将该半抗原分别与牛血清白蛋白(BSA)和卵清白蛋白(OVA)进行偶联得到全抗原,经紫外光谱法鉴定后,用三硝基苯磺酸法(TNBS)测得2偶联物偶联比分别为22:1和15:1.以CFP-NH2-BSA免疫新西兰白兔、CFP-NH2-OVA为包被原,对其抗血清进行间接竞争酶联免疫吸附测定(ELISA),测得抗血清效价为2.56×104,抗血清竞争性抑制试验表明,溴虫腈质量浓度为40 μg/mL时,其抑制率达80%以上,进一步证明抗原合成成功.     

二氯喹啉酸人工抗原的合成

以3,7-二氯-8-喹啉羧酸、草酰氯、5-氨基戊酸(Q-5)为原料合成二氯喹啉酸半抗原,再采用碳二亚胺法将半抗原与载体蛋白[牛血清蛋白(BSA)、鸡卵清蛋白(OVA)]偶联合成相应的人工抗原。将半抗原用红外(IR)和核磁共振(1H-NMR)进行结构表征,通过紫外扫描证明二氯喹啉酸人工抗原(Q-5-BSA、Q-5-OVA)合成成功,且Q-5-BSA、Q-5-OVA的结合比分别为21∶1、17∶1。人工抗原的合成为研制二氯喹啉酸多克隆抗体及免疫试剂盒奠定了基础。     

环丙氨嗪人工抗原的合成与鉴定

本研究拟通过抗原合成、多克隆抗体制备等途径建立快速的环丙氨嗪酶联免疫检测方法.主要采用戊二醛桥连法,偶联半抗原环丙氨嗪和载体牛血清白蛋白(BSA)或卵清白蛋白(OVA),制备酶联检测的免疫抗原和包被抗原.经紫外光谱和气相-傅里叶-红外光谱鉴定,在紫外265 nm波长处得到环丙氨嗪-BSA吸收峰;在红外3 350～3 300 cm-1、1 660～1 500 cm-1和1 695～1 665 cm-1波长处分别得到环丙氨嗪-BSA和环丙氨嗪-OVA特征性偶联吸收峰,证实本试验人工合成的2对抗原均偶联成功.免疫抗原和包被抗原的偶联比分别达到25.9 ∶ 1、23.1 ∶ 1,为进一步制备抗血清和酶联检测方法的建立奠定了工作基础.     

培氟沙星人工抗原的合成与鉴定

【目的】制备培氟沙星(Pefloxacin,PEF)完全抗原,并对其免疫学特性进行鉴定。【方法】以培氟沙星与牛血清白蛋白(BSA)为材料,用碳二亚胺(EDC)法制备培氟沙星-牛血清白蛋白完全抗原(PEF-BSA),变性聚丙烯酰胺凝胶电泳(SDS-PAGE)及紫外扫描(UV)检测其免疫学特性;利用PEF-BSA免疫BALB/c小鼠,无菌条件下收集血清,用间接ELISA测定多抗血清(pAb)效价。并用同样的方法制备和鉴定培氟沙星-鸡卵清白蛋白完全抗原(PEF-OVA)。【结果】培氟沙星与牛血清白蛋白及鸡卵清白蛋白偶联成功,PEF-BSA偶联比为8∶1,PEF-OVA偶联比为6∶1。间接ELISA测得多抗血清效价均达到4 000以上,得到了较好的免疫效果。【结论】成功得到了培氟沙星完全抗原,该抗原具有较强的特异性及良好的敏感性。     

诺氟沙星多克隆抗体的制备

为了制备诺氟沙星(NFLX)抗体,将修饰成功的NFLX-NH2分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)偶联,制备完全抗原,用免疫抗原免疫小鼠,获得了高效价的诺氟沙星多克隆抗体.     

Aminoguanidine prevents diabetes-induced arterial wall protein cross-linking

Age-associated increases in collagen cross-linking and accumulation of advanced glycosylation products are both accelerated by diabetes, suggesting that glucose-derived cross-link formation may contribute to the development of chronic diabetic complications as well as certain physical changes of aging. Aminoguanidine, a nucleophilic hydrazine compound, prevented both the formation of fluorescent advanced nonenzymatic glycosylation products and the formation of glucose-derived collagen cross-links in vitro. Aminoguanidine administration to rats was equally effective in preventing diabetes-induced formation of fluorescent advanced nonenzymatic glycosylation products and cross-linking of arterial wall connective tissue protein in vivo. The identification of aminoguanidine as an inhibitor of advanced nonenzymatic glycosylation product formation now makes possible precise experimental definition of the pathogenetic significance of this process and suggests a potential clinical role for aminoguanidine in the future treatment of chronic diabetic complications.     

Protein conformation in solution: cross-linking of lysozyme

The cross-linking of lysozyme by reaction with phenol-2,4-disulfonyl chloride has been effected. The cross-linked protein retained enzymatic activity, has approximately the same molecular weight as native lysozyme, and has essentially the same conformation as native lysozyme as judged by optical rotatory dispersion analysis. The positions of sulfonylation were assigned by a standard degradation sequence; the presence of sulfonamide bonds was confirmed by infrared spectroscopy. Cross-links may thus be introduced without incurring major structural changes in the protein, and certain intramolecular distances that are allowed in the active enzyme may be deduced.     

Antifungal agent

From the soil of the San Joaquin Valley a fungus has been isolated, an extract of which inhibits the growth of Coccidioides immitis on Sabouraud's medium. An acute toxicity study in mice indicates a certain tolerance of the extract. Tentative identification indicates that the fungus is a penicillium.     

交联改性前后壳聚糖的纤维素酶固定效率研究

为了探讨交联改性前后壳聚糖的纤维素酶固定化效率,先将CTS季铵化,得到改性壳聚糖季铵盐(HACC),再以固定化酶量、最适温度、最适pH值和米氏常数等为指标,分析交联改性前后壳聚糖的纤维素酶固定化效率.结果为,改性壳聚糖作为载体提高了固定化酶的量,同时提高了固定化酶最适温度(P<0.05),最适pH值也有所增加(P>0.05),米氏常数分别为Km,改 =34.7 mg/L,普s=36.9 mg/L.得出结论,改性壳聚糖作为载体提高了纤维素酶的固定化效率.     

Global flexibility in a sensory receptor: a site-directed cross-linking approach

The aspartate receptor of Escherichia coli and Salmonella typhimurium is a cell surface sensory transducer that binds extracellular aspartate and sends a transmembrane signal to the inside of the bacterium. The flexibility and allostery of this receptor was examined by placing sulfhydryl groups as potential cross-linking sites at targeted locations in the protein. Seven different mutant receptors were constructed, each containing a single cysteine residue at a different position in the primary structure. Intramolecular disulfide bond formation within oligomers of these mutant receptors is shown to trap structural fluctuations and to detect ligand-induced changes in structure. The results indicate that the receptor oligomer has a flexible, dynamic structure which undergoes a global change upon aspartate binding.     

Novel interleukin-2 receptor subunit detected by cross-linking under high-affinity conditions

Interleukin-2 (IL-2) binds to both high- and low-affinity classes of IL-2 receptors on activated T lymphocytes. Only the high-affinity receptors are involved in receptor-mediated endocytosis and normally transduce the mitogenic signals of IL-2; however, the structural features distinguishing the high- and low-affinity receptors are unknown. When 125I-labeled IL-2 was chemically cross-linked to activated human T lymphocytes, two major bands were identified. First, as predicted, a 68- to 72-kilodalton band, consisting of IL-2 (15.5 kilodaltons) cross-linked to the IL-2 receptor (55 kilodaltons), was observed. Second, an unpredicted 85- to 92-kilodalton moiety was detected. This band was not present when IL-2 was cross-linked to transfected C127 cells, which exclusively express low-affinity receptors. The data presented are most consistent with the existence of a 70- to 77-kilodalton glycoprotein subunit (p70) which, upon associating with the 55-kilodalton low-affinity receptor (p55), transforms it into a high-affinity site. It is proposed that p55 and p70 be referred to as the alpha and beta subunits, respectively, of the high-affinity IL-2 receptor.     

Inhibition of collagen fibril formation in vitro and subsequent cross-linking by glucose

Glucose inhibits collagen fibril formation in vitro. A linear dose response was observed, with half-maximum inhibition of fibril formation occurring at 50 mM glucose. Nonfibrillar collagen cannot be cross-linked by lysyl oxidase, an enzyme that catalyzes the initial cross-linking reaction. The degree of decreased fibril formation correlated with the loss of ability of the collagen to serve as a substrate for lysyl oxidase. Collagen that is not cross-linked is unstable and more susceptible to collagenolytic attack. Interference with collagen cross-linking and more rapid degradation may explain the decreased amounts of interstitial collagen and the poor healing of wounds associated with diabetes mellitus.