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Probing iso-1-cytochrome c structure by site-directed spin labeling and electron paramagnetic resonance techniques

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Pyka J., Osyczka A., Turyna B., Blicharski W., Froncisz W.

Acta Biochimica Polonica

1999

vol. 46

issue 4

889-899

A cysteine-specific methanethiosulfonate spin label was introduced into yeast iso-1-cytochrome c at three different positions. The modified forms of cytochrome c included: the wild-type protein labeled at naturally occurring C102, and two mutated proteins, S47C and L85C, labeled at positions 47 and 85, respectively (both S47C and L85C derived from the protein in which C102 had been replaced by threonine). All three spin-labeled protein derivatives were characterized using electron paramagnetic resonance (EPR) techniques. The continuous wave (CW) EPR spectrum of spin label attached to L85C differed from those recorded for spin label attached to C102 or S47C, indicating that spin label at position 85 was more immobilized and exhibited more complex tumbling than spin label at two other positions. The temperature dependence of the CW EPR spectra and CW EPR power saturation revealed further differences of spin-labeled L85C. The results were discussed in terms of application of the site-directed spin labeling technique in probing the local dynamic structure of iso-1-cytochrome c.

Pulmonary metastases of the A549-derived lung adenocarcinoma tumors growing in nude mice. A multiple case study

73%

Jakubowska M., Śniegocka M., Podgórska E., Michalczyk-Wetula D., Urbanska K., Susz A., Fiedor L., Pyka J., Płonka P.

2013

vol. 60

issue 3

323-330

Lung adenocarcinoma is a leading human malignancy with fatal prognosis. Ninety percent of the deaths, however, are caused by metastases. The model of subcutaneous tumor xenograft in nude mice was adopted to study the growth of control and photodynamically treated tumors derived from the human A549 lung adenocarcinoma cell line. As a side-result of the primary studies, observations on the metastasis of these tumors to the murine lungs were collected, and reported in the present paper. The metastasizing primary tumors were drained by a prominent number of lymphatic vessels. The metastatic tissue revealed the morphology of well-differentiated or trans-differentiated adenocarcinoma. Further histological and histochemical analyses demonstrated the presence of golden-brown granules in the metastatic tissue, similar to these found in the tumor tissue. In contrast to the primary tumors, the electron paramagnetic resonance spectroscopy revealed no nitric oxide - hemoglobin complexes (a source of intense paramagnetic signals), in the metastases. No metastases were found in other murine organs; however, white infarctions were identified in a single liver. Taken together, the A549-derived tumors growing subcutaneously in nude mice can metastasize and grow on site in the pulmonary tissue. Thus, they can represent an alternative for the model of induced metastatic nodule formation, following intravenous administration of the cancerous cells.

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2 Acta Biochimica Polonica

1 2013

1 1999

2 Pyka J.

1 Blicharski W.

1 Fiedor L.

1 Froncisz W.

1 Jakubowska M.

1 Michalczyk-Wetula D.

1 Osyczka A.

1 Podgórska E.

1 Płonka P.

1 Susz A.

1 Turyna B.

1 Urbanska K.

1 Śniegocka M.

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Probing iso-1-cytochrome c structure by site-directed spin labeling and electron paramagnetic resonance techniques

Pulmonary metastases of the A549-derived lung adenocarcinoma tumors growing in nude mice. A multiple case study