A soluble matrix protein P14 with an apparent molecular mass of 14.5 kDa was isolated from fragmented nacre of pearl oysters （Pinctada fucata） treated with 10% NaOH solution to investigate the nacre matrix proteins ...A soluble matrix protein P14 with an apparent molecular mass of 14.5 kDa was isolated from fragmented nacre of pearl oysters （Pinctada fucata） treated with 10% NaOH solution to investigate the nacre matrix proteins and their effect on the CaCO3 crystal. The protein was characterized by gel exclusion chromatography and reversed-phase high performance liquid chromatography after demineralization by 10% acetic acid. The X-ray diffraction pattern of P14 crystals indicates that P14 plays an important role in nacre biomineralization. P14 can induce aragonite formation, stimulate CaCO3 crystal formation, and accelerate aragonite precipitation. Heating of the acid insoluble nacre residue, which was named conchiolin, in 10% sodium dodecyl sulfate solution supplemented with 10% β-mercaptoethanol solution for 10-20 min at about 100℃ gave two other soluble proteins having molecular masses of 19.4 kDa and 25.0 kDa. The present study suggests that these two proteins are linked to the insoluble organic matrix by disulfide bridges because the extraction yield increases when β-mercaptoethanol is added to the medium.展开更多
The effects of genistein on several tumor cell lines were investigated to study the effects of genistein on cell growth, cell cycle, and apoptosis of two murine melanoma cell lines, B16 and K1735M2. These two closely ...The effects of genistein on several tumor cell lines were investigated to study the effects of genistein on cell growth, cell cycle, and apoptosis of two murine melanoma cell lines, B16 and K1735M2. These two closely related murine melanoma cell lines, however, have different responses to the genistein treatment. Genistein inhibits the growth of both the B16 and K1735M2 cell lines and arrests the growth at the G2/M phase. After treatment with 60 μmol/L genistein for 72 h, apoptosis and caspase activities were detected in B16 cells, while such effects were not found treatment the protein content and mRNA levels of n K1735M2. Further tests showed that after genistein p53 increased in B16, but remained the same in K1735M2. The protein content and mRNA levels of p21^WAF1/CIP1 increased in both cell lines after treatment. The results show that genistein might induce apoptosis in B16 cells by damaging the DNA, inhibiting topoisomerase Ⅱ, increasing p53 expression, releasing cytochrome c from the mitochondria, and activating the caspases which will lead to apoptosis.展开更多
基金Supported by the National High-Tech Research and Development (863) Program of China (No. 2003AA603430) and the National Natural Science Foundation of China (No. 30170723)
文摘A soluble matrix protein P14 with an apparent molecular mass of 14.5 kDa was isolated from fragmented nacre of pearl oysters （Pinctada fucata） treated with 10% NaOH solution to investigate the nacre matrix proteins and their effect on the CaCO3 crystal. The protein was characterized by gel exclusion chromatography and reversed-phase high performance liquid chromatography after demineralization by 10% acetic acid. The X-ray diffraction pattern of P14 crystals indicates that P14 plays an important role in nacre biomineralization. P14 can induce aragonite formation, stimulate CaCO3 crystal formation, and accelerate aragonite precipitation. Heating of the acid insoluble nacre residue, which was named conchiolin, in 10% sodium dodecyl sulfate solution supplemented with 10% β-mercaptoethanol solution for 10-20 min at about 100℃ gave two other soluble proteins having molecular masses of 19.4 kDa and 25.0 kDa. The present study suggests that these two proteins are linked to the insoluble organic matrix by disulfide bridges because the extraction yield increases when β-mercaptoethanol is added to the medium.
文摘The effects of genistein on several tumor cell lines were investigated to study the effects of genistein on cell growth, cell cycle, and apoptosis of two murine melanoma cell lines, B16 and K1735M2. These two closely related murine melanoma cell lines, however, have different responses to the genistein treatment. Genistein inhibits the growth of both the B16 and K1735M2 cell lines and arrests the growth at the G2/M phase. After treatment with 60 μmol/L genistein for 72 h, apoptosis and caspase activities were detected in B16 cells, while such effects were not found treatment the protein content and mRNA levels of n K1735M2. Further tests showed that after genistein p53 increased in B16, but remained the same in K1735M2. The protein content and mRNA levels of p21^WAF1/CIP1 increased in both cell lines after treatment. The results show that genistein might induce apoptosis in B16 cells by damaging the DNA, inhibiting topoisomerase Ⅱ, increasing p53 expression, releasing cytochrome c from the mitochondria, and activating the caspases which will lead to apoptosis.
