Characteristic infrared spectroscopic patterns in the protein bands of human breast cancer tissue

Infrared (IR) spectra of normal, hyperplasia, fibroadenoma and carcinoma tissues of human breast obtained from 96 patients have been determined and analyzed statistically. Several spectral differences were detected in the frequency regions of N-H stretching, amide I, II and III bands: (1) the bands in the region 3000-3600cm-1 shifted to lower frequencies for the carcinomatous tissue; (2) the A(3300)/A(3075) absorbance ratio was significantly higher for the fibroadenoma than for the other types of tissues; (3) the frequency of the a-helix amide I band decreased for the malignant tissue, while the corresponding beta -sheet amide I band frequency increased; (4) the A(1657)/A(1635) and A(1553)/A(1540) absorbance ratios were the highest for fibroadenoma and carcinoma tissues; (5) the A(1680)/A(1657) absorbance ratio decreased significantly in the order of normal > hyperplasia > fibroadenoma > carcinoma; (6) the A(1651)/A(1545) absorbance ratio increased slightly for the fibroadenoma and the carcinoma tissues; (7) the bands at 1204 and 1278 cm(-1), assigned to the vibrational modes of the collagen, did not appear in the original spectra as resolved peaks and were distinctly stronger in the deconvoluted spectra of the carcinoma tissue and (8) the A(1657)/A(1204) and A(1657)/A(1278) absorbance ratios, both yielding information on the relative content of collagen, increased in the order of normal < hyperplasia < carcinoma < fibroadenoma. The said differences imply that the information is useful for the diagnosis of breast cancer and malignant breast abnormalities, and may serve as a basis for further studies on conformational changes in tissue proteins during carcinogenesis. (C) 2001 Elsevier Science B.V. All rights reserved.

Purification of human tissue prokallikrein excreted from insect cells by liquid chromatography

Tissue kallikrein, generally existing in living bodies as prokallikrein, is a serine proteinase that has proven of great significance to treat hypertension, cardiopathy and nephropathy. Although the extraction of tissue kallikrein from human urine is the most commonly used method to obtain such a protein, not only the yield is very little, but also the procedure is rather complex. Furthermore, the biological safety is uncertain. Therefore, the preparation of such a protein by genetic engineering method, including gene expression, cell culture, separation and purification, is very important. In this paper, a new method to obtain purified tissue prokallikrein excreted from insect cells by liquid chromatography has been proposed. In contrast to the previously published papers, the purification procedure is simplified to only three steps with the final yield of 57% and the purity of 95%, which is not only convenient, but also low-cost and suitable for the large-scale preparation of such a protein. The purified protein is further validated as prokallikrein by high performance liquid chromatography-mass spectrometry and amino acid sequencing. (c) 2005 Elsevier B.V. All rights reserved.