大鲵低聚糖肽性质初步研究

采用化学方法对大鲵低聚糖肽的氨基酸组成、糖组成及糖肽连接方式进行了初步研究。结果表明,大鲵低聚糖肽含蛋白量为80.01%、总糖含量为15.15%。其含有的氨基葡萄糖、葡萄糖醛酸、半乳糖醛酸及唾液酸分别为3.39%、0.65%、2.45%和0.60%。其氨基酸组成中,苏氨酸的含量最高,达13.1%,其次是脯氨酸、丙氨酸、亮氨酸、精氨酸、苯丙氨酸等。大鲵低聚糖肽的β-消旋反应和血凝集反应,表明大鲵低聚糖肽中糖肽键以O-连接的形式存在。     

hCG受体的结合特性及卵清蛋白的抑制作用

本文采用Ｉｏｄｏｇｅｎ固相氧化法制备高活性１２５Ｉ—ｈＣＧ，建立了大鼠睾丸细胞膜制齐ｈＣＧ受体－放射配基结合分析法．１２５Ｉ—ＨＣＧ与受体的结合具有可饱和性、可逆性和特异性等基本特征．在所用１２５Ｉ—ｈＣＧ浓度范围内，Ｓｃａｔｃｈａｒｄ分析为直线，Ｈｉｌｌ系数接近玉，属简单单位点系统．卵清蛋白糖肽可抑制１２５ｈＣＧ与受体的结合，其ＫＩ为３５．１±７．１ｎｍ，ＩＣ５０为５９．５±１１．９ｕｍ，经ＬＩＧＡＮＤ软看数据处理表明，这种抑制作用亦属简单单位点系统，提示ｈＣＧ—Ａｓｎ—连接的寡糖链并非与膜上凝集素样成分结合，而是直接参与ｈＣＧ与受体分子的相互作用，卵清蛋白糖肽Ａｓｎ—连接的糖链可干扰ｈＣＧ糖链与受体的结合．     

Conformation Analysis of GalNAc‐Appended Sugar Amino Acid Foldamers as Glycopeptide Mimics

Sugar amino acid (SAA)‐based foldamers with well‐defined secondary structures were appended with N‐acetylgalactosamine (GalNAc) sugars to access sequence‐defined, multidentate glycoconjugates with full control over number, spacing and position. Conformation analysis of these glycopeptides by extensive NMR spectroscopic studies revealed that the appended GalNAc units had a profound influence on the native conformational behaviour of the SAA foldamers. Whereas the 2,5‐cis glycoconjugate showed a helical structure in water, comprising of two consecutive 16‐membered hydrogen bonds, its 2,5‐trans congener displayed an unprecedented 16/10‐mixed turn structure not seen before in any glycopeptide foldamer.     

A Synthetic MUC1 Glycopeptide Bearing βGalNAc‐Thr as a Tn Antigen Isomer Induces the Production of Antibodies against Tumor Cells

This study presents the synthesis of the novel protected O‐glycosylated amino acid derivatives 1 and 2 , containing βGalNAc‐SerOBn and βGalNAc‐ThrOBn units, respectively, as mimetics of the natural Tn antigen (αGalNAc‐Ser/Thr), along with the solid‐phase assembly of the glycopeptides NHAcSer‐Ala‐Pro‐Asp‐Thr[αGalNAc]‐Arg‐Pro‐Ala‐Pro‐Gly‐BSA ( 3 ‐BSA) and NHAcSer‐Ala‐Pro‐Asp‐Thr[βGalNAc]‐Arg‐Pro‐Ala‐Pro‐Gly‐BSA ( 4 ‐BSA), bearing αGalNAc‐Thr or βGalNAc‐Thr units, respectively, as mimetics of MUC1 tumor mucin glycoproteins. According to ELISA tests, immunizations of mice with βGalNAc‐glycopeptide 4 ‐BSA induced higher sera titers (1:320 000) than immunizations with αGalNAc‐glycopeptide 3 ‐BSA (1:40 000). Likewise, flow cytometry assays showed higher capacity of the obtained anti‐glycopeptide 4 ‐BSA antibodies to recognize MCF‐7 tumor cells. Cross‐recognition between immunopurified anti‐βGalNAc antibodies and αGalNAc‐glycopeptide and vice versa was also verified. Lastly, molecular dynamics simulations and surface plasmon resonance (SPR) showed that βGalNAc‐glycopeptide 4 can interact with a model antitumor monoclonal antibody (SM3). Taken together, these data highlight the improved immunogenicity of the unnatural glycopeptide 4 ‐BSA, bearing βGalNAc‐Thr as Tn antigen isomer.     

玉米糖肽的纳滤脱盐工艺

为了去除玉米糖肽溶液中过多的盐分,采用相对分子质量200纳滤膜对具有抗氧化活性的玉米糖肽溶液进行脱盐处理,通过对膜通量以及玉米糖肽溶液的Na+质量分数、脱盐率、电导率、短肽回收率和纳滤后产物自由基清除率和Fe2+-螯合率等参数的研究,确定玉米糖肽溶液的纳滤脱盐工艺.结果表明,利用相对分子质量200纳滤膜对玉米糖肽溶液脱...     

大鲵糖肽润肤霜的制备及性能评价

通过添加大鲵糖肽制备了润肤霜,探讨了大鲵糖肽的吸湿性与抗氧化性,大鲵糖肽润肤霜的抗紫外线性与豚鼠皮肤涂抹的变态反应。结果表明：在低湿度条件下,大鲵糖肽的吸湿率达3.8%,在高湿度条件下,大鲵糖肽的吸湿率达15.6%;羟基自由基清除率为50.85%;添加了大鲵糖肽在260～315 nm下具有较强紫外线吸收能力;涂抹大鲵糖肽润肤霜和大鲵糖肽的豚鼠皮肤没有出现任何的红斑和水肿,与对照组的豚鼠的皮肤一致。