离子交换法提取发酵液中唾液酸

研究了离子交换树脂从发酵液中提取唾液酸的方法,包括树脂的筛选、吸附条件和洗脱条件的确定,唾液酸纯度达到97.4%.     

聚唾液酸的摇瓶工艺

研究了突变株JYL 11(Escherichiacoli)的摇瓶发酵工艺条件:在山梨醇40g/L,K2HPO420g/L,NH4Cl4g/L,MgSO40.9g/L,蛋白胨1.5g/L,起始pH值7.8,装液量35mL(250mL的三角瓶中),转速250r/min,培养温度37℃,接种量为4%(体积分数)的条件下,聚唾液酸产量达到3.5mg/mL,比优化前提高了1.0mg/mL,提高幅度为40%.     

大肠杆菌产生的聚唾液酸的结构

研究了大肠杆菌产生的聚唾液酸的分子结构，对聚唾液酸的分子基团特征进行了红外光谱分析，研究了聚唾液酸糖苷键的连接方式和构型．发酵液中的聚唾液酸经超滤浓缩、有机沉淀和离子交换层析处理，得到高纯度的聚唾液酸，经^13C-NMR分析和比较，表明所得到的聚唾液酸是一种α-2，8糖苷键连接的同聚物。     

大肠杆菌60Co诱变育种及其发酵生产聚唾液酸条件

对产聚唾液酸菌株大肠杆菌WX J11进行6 0 Co诱变 ,筛选出高产突变株WX J4 ,其聚唾液酸产量可达 10 0 1mg/L ,通过优化发酵条件即在 2 50mL的摇瓶中 ,2 50r/min转速下 ,37℃恒温培养 6 5h ,起始 pH值为 7.8,装液量为 4 0mL ,使聚唾液酸的产量提高到 150 0mg/L .聚唾液酸在菌体生长停止后释放到培养基中 ,动力学上表现为次级代谢产物 .此外 ,还对聚唾液酸的提取、水解和唾液酸的纯化作了初步研究 .     

NTG对E.coli突变株聚唾液酸产量的影响

在不同的 pH条件下 ,用NTG连续处理E .coli,得到突变菌株JYⅡ 74 ;摇瓶培养 ,发酵液中聚唾液酸产量达 2 80 0mg/L ,比出发菌株提高了 130 0mg/L ,提高幅度为 72 .5 % ,且生产能力稳定 .提取发酵液中的聚唾液酸 ,红外光谱鉴定其纯度 ,13C核磁共振图谱表明 ,该多糖是一种α 2 ,8糖苷键连接的唾液酸同聚物 .     

唾液酸测定与肺癌诊断相关性的研究

应用酶法测定药盒对５４例胸部肿瘤患者进行了血清唾液酸（ＳＡ）测定，以探讨ＳＡ对肺癌的诊断价值。结果提示：肺癌患者ＳＡ水平显著增高（Ｐ＜０．０５），但无特异性。ＳＡ结合其他辅助检查，对肺癌的诊断及疗效观察有一定实用价值；也可用于肺癌高发人群的普查，以及良性和恶性肿癌的鉴别。     

血清唾液酸的诊断作用与临床意义

唾液酸的本质是神经氨酸的乙酰化衍生物。早年认为系由肿瘤细胞所分泌，并将其作为肿瘤标志，用于病人胸、腹水肿瘤的鉴别论断。近年研究发现，血清唾液酸浓度升高的心血管病人群中，残废率相应升高。而且随着受检人员的年龄增大，血清唾液酸测定值也逐渐升高。因而认为，本检查对肿瘤的辅助诊断、疗效估计、心血管病预后的判断及衰老机理的研究均具有重要意义。     

雪旺细胞浆神经营养蛋白高效液相分离纯化及其生物活性研究

目的　分离纯化雪旺细胞浆神经营养蛋白并研究其生物活性。方法　取 30 0只出生后 1～ 3天SD大鼠双侧坐骨神经 ,纯化培养 ,收集雪旺细胞 ,超声粉碎 ,超速离心 ,不同孔径分子筛滤膜 (PM10、30、5 0 )超滤浓缩 ,收集分子量 10～ 30 ku,30～ 5 0 ku和 >5 0 ku三种组份胞浆蛋白浓缩液 ,分别加入体外无血清培养的 E14SD胎鼠脊髓运动神经元培养液中 ,用 MTT酶标法检测证实 10～ 30 ku和 >5 0 ku两组份蛋白有神经营养活性。再通过Diol- 15 0高效液相分子层析进一步从雪旺细胞胞浆中纯化分离出分子量为 2 6 ku和 5 8ku两种胞浆蛋白 ,并对其神经生物活性进行研究。结果　 2 6 ku和 5 8ku雪旺细胞胞浆蛋白能维持体外无血清培养的脊髓运动神经元存活 ,其最佳生物活性浓度为 2 0 ng/孔。结论　雪旺细胞胞浆内含有分子量为 2 6 ku和 5 8ku的运动神经营养蛋白     

pH值对聚唾液酸分批发酵的影响及补料发酵

研究了不同pH值对聚唾液酸发酵过程中菌体生长和产聚唾液酸的影响.发酵初期pH自然下降时有利于菌体生长,菌体生长对数期较长,最大菌体干重可达6.9g/L;发酵中后期pH控制在6.4时有利于聚唾液酸的延续合成,合成对数期比其它pH条件下的合成对数期延长了11h.动力学特性表现为部分相关模式,而在其它pH条件下,动力学特性表现为相关模式.对聚唾液酸的流加补料发酵进行了初步研究,最终使菌体干重达到11.16g/L,聚唾液酸产量达到2.606g/L.     

大鼠精索静脉曲张模型附睾中丙二醛、总抗氧化物及唾液酸含量的改变及意义

目的:探讨大鼠左侧精索静脉曲张后同侧附睾组织中丙二醛(MDA)、总抗氧化物(TAC)和附睾管腔中唾液酸(SA)含量的改变及意义。方法:用8只雄性SD大鼠建立左侧精索静脉曲张模型,另取8只SD大鼠作为对照组。硫代巴比妥酸法和铁离子还原法分别检测附睾组织中MDA和TAC含量;5甲-基苯二酚法检测附睾腔液中SA含量。结果:大鼠左侧精索静脉曲张模型建立后的第7 d,同侧附睾组织中MDA和TAC含量,模型组与对照组相比,差异有显著性(P<0.005);附睾管腔液中SA含量,模型组明显低于对照组,差异有显著性(P<0.005)。结论:大鼠左侧精索静脉曲张会导致同侧附睾组织中活性氧增加,TAC含量下降,进而影响到附睾上皮细胞合成和分泌SA的功能。     

Acid phosphatase in the lysosomal and microsomal fractions of human prostatic epithelium

Polyacrylamide gel electrophoresis of acid phosphatase from prostatic tissue reveals one more band than seminal plasma. It was attempted to ascertain which subcellular fraction was responsible for that intracellularly localized enzyme. Prostatic epithelium from patients with prostatic hyperplasia was homogenized, and a lysosomal and microsomal fraction were prepared by differential centrifugation. These two fractions were further centrifuged on an isopycnic Percoll gradient. The intracellularly localized form of acid phosphatase was associated with the lysosomal as well as with the microsomal fraction. In a fused rocket electrophoresis experiment these acid phosphatases cross-reacted with antiserum from seminal plasma. After neuraminidase treatment of the acid phosphatase of lysosomal and microsomal origin, only one activity band was found in polyacrylamide gels. It is concluded that only one acid phosphatase protein exists in prostatic epithelium; differences in electrophoretic mobility are caused mainly by different amounts of sialic acid residues, coupled to the same protein backbone.     

Studies on the structural basis of the heterogeneity of human prostatic and seminal acid phosphatases

We studied possible causes of the electrophoretic heterogeneity of the acid phosphatase (EC 3.1.3.2) purified by affinity chromatography from human prostate and human seminal fluid. The isoelectric focusing pattern in polyacrylamide gel shows numerous bands in the pH range 4.0-5.2 and 5.5-5.9. Treatment with neuraminidase under conditions shown to cause complete removal of sialic acid does not abolish the observed heterogeneity. Although there is a change of the more acidic forms to ones having more basic pI values, at least 4 distinct bands remain. Structural differences at the amino terminal end can be ruled out as the cause of the remaining electrophoretic heterogeneity. Lysine is shown to be the amino terminal amino acid for both the prostatic and seminal fluid enzymes. The sequences of the first 23 amino acids are shown to be identical for the prostatic and seminal fluid acid phosphatases. The functional enzyme contains no metal ion but it can be stoichiometrically inactivated by cupric ion.     

Surface activity on the periosteal and corticoendosteal envelopes following continuous progestogen supplementation in spayed Beagles

Summary High performance liquid chromatography was used to resolve O-phosphoserine, O-phosphothreonine, and O-phosphotyrosine as their fluorescent o-phthalaldehyde derivatives. By adjusting the buffer system, very small amounts of O-phosphothreonine could be detected and quantitated in the presence of very large amounts of O-phosphoserine. In addition, γ-carboxyglutamic acid and glutamic acid were also separated and quantitated. Depending on the buffer used, various combinations of these amino acids could be resolved in a single run.