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Revista de diagnóstico y biomarcadores moleculares

Volumen 3, Asunto 3 (2012)

Artículo de investigación

Characterization of the Interaction between Cationic Thulium (III)–Porphyrin Complex with Bovine Serum Albumin.

Xi-Liang Lu, Huai-Cheng Yang, Hui Wu and An-Xin Hou

The interaction of cationic Thulium (III)–porphyrin complex(Tm–Porp) with Bovine Serum Albumin (BSA) has been investigated by fluorescence quenching spectra. The quenching mechanism of fluorescence was suggested as a static quenching with a highaffinity according to the Stern–Volmer equation. The number of binding sites and the apparent binding constant a K of the Tm–Porp on BSA were explained by a modified Scatchard equation and the site probe competition. The corresponding thermodynamic parameters ΔH0 ,ΔG0 and ΔS0 at different temperatures are discussed. The results indicated that the electrostatic and hydrophobic interactions are the predominant intermolecular forces in stabilizing complex. Binding distance between the donor and acceptor was obtained in terms of Forester’s Non-radiative energy transfer theory. Furthermore, the effects of the Tm-Porp on the BSA configuration were elucidated by Circular Dichroism (CD) spectra method along with UV–Vis absorption and Synchronous Fluorescence Spectroscopy (SFS). The results indicated that the secondary structures of BSA have been perturbed in the presence of drug. Finally, we showed that the cationic Tm–Porp can preferentially bind at the site-I and site-II of BSA with equal occupancy.

Artículo de investigación

Ficolin 1 Expression is Elevated in the Peripheral Blood Mononuclear Cells of Takayasu's Vasculitis Patients

Daisuke Okuzaki, Shigeto Kobayashi, Minami A. Sakurai, Kosuke Torigata, Ayumi Okamoto, Toshiharu Matsumoto, Hiroyuki Daida, Akihiko Ito and Hiroshi Nojima

Takayasu’s arteritis (TA), a form of vasculitis (angiitis), is a chronic inflammatory disease involving the large blood vessels. This study reports the identification of genes showing increased mRNA levels in peripheral blood mononuclear cells (PBMCs) from TA patients regardless of symptoms or disease activity/inactivity. Of these, mRNA for Ficolin 1 (FCN1) showed a four-fold increase in all eight TA patients examined. Increased FCN1 mRNA levels observed in cDNA microarrays were confirmed by quantitative reverse transcription polymerase chain reaction. Increased FCN1 protein expression was also observed in inflamed regions of the surgical aorta specimens. Moreover, most FCN1-positive cells were also positive for CD68, indicating the presence of monocytic cells, such as macrophages or dendritic cells, which attack infectious agents within the inflamed regions. Taken together, the results suggest that FCN1 mRNA levels in peripheral blood samples may be a diagnostic marker for TA.

Artículo de investigación

Identification of Core Proteins Carrying the Sialyl Lewis a Epitope in Pancreatic Cancers

Yoshitoshi Hirao, Satoshi Ogasawara, Akira Togayachi, Yu-ki Matsuno, Makoto Ocho, Keishi Yamashita, Masahiko Watanabe, Shoji Nakamori, Yuzuru Ikehara and Hisashi Narimatsu

Identification of core proteins carrying the CA19-9 (carbohydrate antigen, sialyl Lewis a) epitope from various tissues will improve the diagnosis of pancreatic cancer in terms of specificity and sensitivity. In this study, we attempted to identify sialyl Lewis a-carrier proteins specifically expressed in pancreatic cancer. Pancreatic cancer is difficult to detect in the early stages of the disease, resulting in a high level of mortality. Therefore, in order to determine the correct course of treatment, it is vital to distinguish cancer from obstruction of the bile duct or other diseases. Our strategy to identify the carrier proteins was as follows: glycoproteins carrying sialyl Lewis a antigen were enriched from pancreatic cancer cell lines using anti-sialyl Lewis a antibody and then subjected to Peptide Mass Fingerprinting analysis. Based on these studies we identified nine glycoproteins carrying the sialyl Lewis a epitope. We evaluated candidate molecules by biochemical analyses of culture supernatants and human sera. In particular, we focused on one candidate molecule carrying a sialyl Lewis a epitope, Galectin-3BP/MAC2BP; M2BP, which was analyzed in detail. These results verified that our candidate molecule is a core protein carrying the sialyl Lewis a epitope. Furthermore, we demonstrated sandwich ELISA, which showed that the glycoprotein was able to detect CA19-9 antigen in culture supernatants. Our approach facilitated the identification of the core protein carrying the sialyl Lewis a epitope. We believe our approach will enable future developments in cancer glycobiomarker identification.

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