Sponges (Porifera) are the oldest living metazoan in the world, among which most of them (Demospongia) can produce silicic skeleton from orthosilicic acid in the seawater under the natural enVironmental conditions. These biosilicic materials exhibit good mechanical and optical properties as well as good biocompatibility. During the biosilicification process of sponges, a protein, named as silicatein, plays an important role and has attracted great attention from biologist, chemists and material scientists. This mini review highlights the discovery of silicateins and its function as both an enzymatic catalyst and an organic template for biosilicification. The studies since 1999 were briefly introduced on the application of silicatein as a biocatalyst and template for synthesis of silica-based and other inorganic materials. It is expected to stimulate the interests in the related researches in China.
Animals ; Biocatalysis ; Biocompatible Materials ; Cathepsins ; chemistry ; Porifera ; enzymology ; Silicon Dioxide ; metabolism

Tetraselmis subcordiformis, a marine green alga, can produce hydrogen by photobiologically hydrolyzing seawater with hydrogenase. In this study, the preliminary purification of the enzyme was explored by ammonium sulfate precipitation, and the impact of sodium dithionite, beta-mercaptoethanol and glycerol on the enzyme stability during the process was investigated. The experimental results illustrated that sodium dithionite provided significant protection on the hydrogenase by depleting oxygen, while glycerol, a protectant against the structure instability of the enzyme, also presented protection. Crude enzyme with specific activity of 0.557 U/mg protein was extracted using 60%-70% saturated ammonium sulfate solution supplemented with 200 mmol/L sodium dithionite and 5% glycerol, and the hydrogenase recovery yield was about 30%.
Ammonium Sulfate ; chemistry ; Chemical Precipitation ; Chlorophyta ; enzymology ; Enzyme Stability ; Hydrogen ; metabolism ; Hydrogenase ; isolation & purification ; metabolism ; Seawater

Objective:To analyze the causal relationship between lifestyle-based factors and the occurrence and development of hepatobiliary malignancies by Mendelian randomization study method,and to provide the potential clinical evidence for the prevention and treatment of hepatobiliary malignancies.Methods:The data from large-scale,independent genome-wide association studies(GWAS)were selected,and seven-step inclusion criteria for the instrumental variable screening were set up.The exposure lifestyles included the percentage of carbohydrate intake,percentage of fat intake,percentage of protein intake in the diet,coffee intake,weekly alcohol consumption times,leisure electronic screen exposure time,moderate to vigorous intensity physical activity(MVPA)during leisure time,sedentary behavior at work,age at first smoking,daily smoking quantity,current smoking status,and past smoking status,totaling 12 phenotypes.The primary analysis method used was the random effect model of the inverse variance weighted(IVW)method,and the heterogeneity was detected by Cochrane's Q test and the horizontal pleiotropy was detected by MR-Egger intercept method.Results:The current smoking status was significantly positively correlated with the increasing risk of extrahepatic cholangiocarcinoma(OR=1.607,95%CI:1.113-2.322,P=0.011).Higher coffee intake was causally linked to a higher risk of liver cancer and intrahepatic cholangiocarcinoma(OR=1.000,95%CI:0.999-1.000,P=0.012).In the physical activity,more MVPA was associated with the lower risk of liver cancer and intrahepatic cholangiocarcinoma(OR=0.998,95%CI:0.996-0.999,P=0.002).The Cochrane's Q test results showed that there was mild heterogeneity between MVPA and extrahepatic cholangiocarcinoma(Q=18.354,P=0.049)as well as the percentage of protein intake and intraphepatic cholangiocarainoma(Q=12.715,P=0.026),and the MR-Egger intercept method results showed there was no horizontal pleiotropy.Conclusion:There is a causal relationship between current smoking status and extrahepatic cholangiocarcinoma,and there is a causal relationship between more MVPA and the lower risk of liver cancer and intrahepatic cholangiocarcinoma.Education on smoking and physical activity for the patients may offer potential benefits for the prevention of hepatobiliary malignancies.