The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard was developed for simultaneous determination of ribose and phosphorus contents in Hib CPS.Hexamethylphosphoramide(HMPA)was successfully utilized as an internal standard in quantitative ^(1)H-NMR method for ribose content determination.The ribose and phosphorus contents were found to be affected by the concentration of polysaccharide solution.Thus,15–20 mg·L^(−1) was the optimal concentration range of Hib CPS in D_(2)O solution for determination of ribose and phosphorus contents by this method.The ribose and phosphorus contents obtained by the quantitative NMR were consistent with those obtained by traditional chemical methods.In conclusion,this quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard shows good specificity,accuracy and precision,providing a valuable approach for the quality control of Hib glycoconjugate vaccines.
Tumor-associated carbohydrate antigens(TACAs) are attractive targets for vaccine development. In this context, we described a strategy combining artificial TACA and glycoengineering for cancer vaccine development. A 2,4-ditrophenyl(DNP)-modified GM3 intermediate was synthesized chemoenzymatically and conjugated to keyhole limpet hemocyanin(KLH), and the resulting bioconjugate was tested for its potential as a vaccine candidate. Mice immunological studies revealed that the DNP-modified GM3(GM3-NHDNP) analog elicited strong and rapid immune responses by recruiting anti-DNP antibodies to facilitate the targeted delivery of the vaccine construct to antigen processing cells(APCs). Moreover, the endogenously produced anti-DNP antibodies, together with the elicited antibodies against GM3-NHDNP, may synergistically promote tumor binding and cancer cell death when the cancer cell surfaces are glycoengineered to express the GM3-NHDNP antigen.
Han LinHaofei HongLipeng FengJie ShiZhifang ZhouZhimeng Wu
拉格酵母(Saccharomyces pastorianus)在高浓酿造早期应答高浓度麦汁的基因调控对发酵过程至关重要,但是目前其对高浓度麦汁的应答机制还不明确。选取典型的拉格酵母M14作为研究对象,获得M14菌株在常浓度麦汁与高浓度麦汁处理后的细胞,提取总RNA进行转录组测序分析,提取胞内代谢物进行代谢组检测分析,并考察2种条件下的发酵指标与糖利用情况。转录组分析结果表明,有191个基因显著调整,KEGG(Kyoto encyclopedia of genes and genomes)富集和GO(gene ontology)富集结果表明,差异基因主要在碳代谢与氨基酸代谢途径。代谢组分析结果表明,有30个代谢物存在显著差异,KEGG富集表明,差异代谢物主要存在于氨基酸代谢。进一步分析确定了13个相关的重要基因。该研究探究了拉格酵母对高浓度麦汁在分子水平上的应答机制,为揭示啤酒高浓酿造机制与耐高浓度酵母的选育奠定了基础。
D-Allose and its derivatives play important roles in the field of health care and food nutrition. Pure and well-defined Dallose derivatives can facilitate the elucidation of their structure-activity relationship as an essential step for drug design. The LattrellDax epimerization, refers to the triflate inversion using nitrite reagent, is known as valuable method for the synthesis of rare D-allose derivatives. Here, the influence of protecting group patterns on the transformation efficiency of D-glucose derivatives into synthetically useful D-alloses and D-allosamines via the Lattrell-Dax epimerization was studied. For C3 epimerization of D-glucose derivatives bearing O2-acyl group, an anomeric configuration-dependent acyl migration from O2 to O3 was found. In addition, a neighbouring group participation effect-mediated SN1 nucleophilic substitution of the D-glucosamine bearing C2 trichloroacetamido(TCA) group in the Lattrell-Dax epimerization was dependent upon anomeric configuration. Thus, the effect of anomeric configuration on the LattrellDax epimerization of D-glucose suggests that β-D-glucosides with low steric hindrance at C2 should be better substrates for the synthesis of D-allose derivatives. Significantly, the efficient synthesis of the orthogonally protected D-allose 13 and D-allosamine 18 will serve well for further assembly of complex glycans.
NING Yun-ZhanQIN Chun-JunSUN Wen-BinFU Jun-JieHU JingYIN Jian
