ABSTRACT
Mitochondrion is a semi-autonomous organelle, important for cell energy metabolism, apoptosis, the production of reactive oxygen species (ROS), and Ca homeostasis. Mitochondrial DNA (mtDNA) mutation is one of the primary factors in mitochondrial disorders. Though much progress has been made, there remain many difficulties in constructing cell models for mitochondrial diseases. This seriously restricts studies related to targeted drug discovery and the mechanism and therapy for such diseases. Here we summarize the characteristics of patient-specific immortalized lymphoblastoid cells, fibroblastoid cells, cytoplasmic hybrid (cybrid) cell lines, and induced pluripotent stem cells (iPSCs)-derived differentiation cells in the study of mitochondrial disorders, as well as offering discussion of roles and advances of these cell models, particularly in the screening of drugs.
ABSTRACT
A novel chitinolytic and chitosanolytic bacterium, Sphingomonas sp. CJ-5, has been isolated and characterized. It secretes both chitinase and chitosanase into surrounding medium in response to chitin or chitosan induction. To characterize the enzymes, both chitinase and chitosanase were purified by ammonium sulfate precipitation, Sephadex G-200 gel filtration and DEAE-Sepharose Fast Flow. SDS-PAGE analysis demonstrated molecular masses of chitinase and chitosanase were 230 kDa and 45 kDa respectively. The optimum hydrolysis conditions for chitinase were about pH 7.0 and 36 degrees C, and these for chitosanase were pH 6.5 and 56 degrees C, respectively. Both enzymes were quite stable up to 45 degrees C for one hour at pH 5~8. These results show that CJ-5 may have potential for industrial application particularly in recycling of chitin wastes.
Subject(s)
Chitinases , Metabolism , Enzyme Stability , Fermentation , Glycoside Hydrolases , Metabolism , Hydrogen-Ion Concentration , SphingomonasABSTRACT
Microbiology is an important basic course of biological subject.Base on using different modern means,the teaching method was explored and attempted,such as quiz teaching,discussion teaching,inductive teaching and teaching check.It is possible for students to be- come main part for teaching course,and student enthusiasm for study was mobilized.