Progresses of Single Molecular Fluorescence Resonance Energy Transfer in Studying Biomacromolecule Dynamic Process / 分析化学

Biomacromolecules participate in various kinds of vital processes. Observing and analyzing their structural dynamic and the dynamic processes of intermolecular interaction at molecular level is important for understanding the action mechanism. Since its advent, single molecular fluorescence resonance energy transfer (SM-FRET) has demonstrated its great potential in studying the conformational change and interaction process of biomacromolecules, and a series of new mechanisms have been revealed. This review summarized recent progresses of SM-FRET in studying protein structural dynamic, nucleic acid structural dynamic, protein-protein and protein-nucleic acid interactions.

Relationship between the expression of human leukocyte antigen-b in peripheral blood leukocytes and the differentiation and metastasis of gastric carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the expression of host human leukocyte antigen-B mRNA (HLA-B mRNA) and HLA-B antigen in peripheral blood leukocytes (PBLs) and the differentiation and metastasis of gastric carcinoma (GC).</p><p><b>METHODS</b>To design and screen specific primers of HLA-B gene independently, detect the expression of HLA-B mRNA from 30 GC patients by reverse transcription-PCR and compare with the HLA-B antigen expression measured by flow cytometry.</p><p><b>RESULTS</b>The expression rate of PBL HLA-B mRNA from GC patients (23. 3% ) was very significantly lower than that of normals (87. 5% ) (P <0. 01) , especially concerning the poorly differentiated GC patients with lymph node metastasis (16. 0% ). Measured by flow cytometry, the expression percentage of HLA-B antigen of well-differentiated GC patients without lymph node metastasis was 88. 2% , an obviously decreasing tendency was showed in comparison with that in the normal group (98. 8% ) , although the difference was not significant (P = 0. 056) , and the expression percentage in poorly differentiated GC patients with lymph node metastasis(73. 3% )was declined significantly (P <0. 05).</p><p><b>CONCLUSION</b>The expression of PBL HLA-B mRNA and HLA-B antigen in GC patients is decreased or lost, and correlated with differentiation and metastasis of the cancer. The expression of PBL HLA-B mRNA may more directly reflect its relationship with the tumor differentiation and metastasis than that of HLA-B antigen.</p>