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Background: Arteriosclerosis has genetic correlation. Many studies have shown that angiotensin II type 1 receptor (AT1R) gene A1166C polymorphism is highly associated with arteriosclerosis, but there is no evidence-based basis. The purpose of this study is to systematically evaluate the relationship between AT1R gene A1166C polymorphism and arteriosclerosis., Methods: The search time is set from the establishment of the database in December 2020 in this study. The search database include China National Knowledge Infrastructure (CNKI), Wanfang, VIP and China Biology Medicine disc (CBM), PubMed, EMBASE, Web of Science, and the Cochrane Library. The subjects are observational studies on the relationship between AGTR1 A1166C polymorphism and arteriosclerosis (including case-control study, cross-sectional study, and cohort study). The language is limited to English and Chinese. The data of the included study are extracted and the literature quality is evaluated by 2 researchers independently. The data are statistically analyzed by Stata 16.0 software., Results: This study will use pulse wave velocity as an index to evaluate arteriosclerosis to explore the relationship between AT1R gene A1166C polymorphism and arteriosclerosis., Conclusion: This study will provide evidence-based medicine for elucidating the genetic tendency of arteriosclerosis., Ethics and Dissemination: Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval will not be required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences., Osf Registration Number: DOI 10.17605/OSF.IO/V6E2Y., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

The thermoacidophilic archaeon Sulfolobus solfataricus P2 encodes three hypothetic endo-beta-glucanases, SSO1354, SSO1949 and SSO2534. We cloned and expressed the gene sso1949 encoding the 334 amino acids containing protein SSO1949, which can be classified as a member of glycoside hydrolase family 12. The purified recombinant enzyme hydrolyses carboxymethylcellulose as well as cello-oligomers, with cellobiose and cellotriose as main reaction products. By following the hydrolysis of a fluorescently labelled cellohexaoside under a wide variety of conditions, we show that SSO1949 is a unique extremophilic enzyme. This archaeal enzyme has a pH optimum of approx. pH 1.8 and a temperature optimum of approx. 80 degrees C. Furthermore, the enzyme is thermostable, with a half-life of approx. 8 h at 80 degrees C and pH 1.8. The thermostability is strongly pH-dependent. At neutral pH, the thermal inactivation rate is nearly two orders of magnitude higher than at pH 1.8. Homology modelling suggests that the catalytic domain of SSO1949 has a similar fold to other mesophilic, acidophilic and neutral cellulases. The presence of a signal peptide indicates that SSO1949 is a secreted protein, which enables S. solfataricus to use cellulose as an external carbon source. It appears that SSO1949 is perfectly adapted to the extreme environment in solfataric pools. A cellulolytic enzyme with such a combination of stability and activity at high temperatures and low pH has not been described so far and could be a valuable tool for the large-scale hydrolysis of cellulose under acidic conditions.