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Objective: To explore the role of 19S regulator compound protein in the degradation of skeletal muscle protein in scalded rats., Methods: Wistar rats were scalded and they were randomly divided into normal and 1, 2, 3, 5, and 7 postburn day (PBD) groups with 8 rats in each group. The 19S regulator compound of skeletal muscle in scalded rats was isolated and purified with chromatography. Rabbit-anti-rat antibody IgG of 19S regulator compound was prepared conventionally. The antibody was injected to rats in injection group (I) in which 19S antibody in dose of 3 mg/kg BW was injected for two times via tail vein with 6-hour interval. The rats in I group were decapitated on 1, 2 and 3 post-injection days, respectively. The scalded rats in control group (C) were treated in the same way, except that the antibody was replaced by normal saline. The change in content of 19S regulator compound was determined by western-blot. Meanwhile, the releasing rate of tyrosine from the skeletal muscle of scalded rats was also detected by fluorescent photography., Results: 19S regulator compound with high purity was obtained. The content of 19S regulator compound in rat skeletal muscle was increased significantly after 2 PBD. But the protein degradation rate was also obviously increased on 2 PBD. The antibody of 19S compound might inhibit the enhancement of protein degradation., Conclusion: Burn injury might up-regulate the protein level of skeletal muscle 19S regulator compound, which therefore activated the protein degradation by 26S protease compound. This might be an important factor leading to postburn negative nitrogen balance.

DNA mismatch repair gene mutS (2.56 kb) was PCR modified and cloned into a secretive prokaryotic expression vector pET32a (+) which carries a N-terminal His.tag + and thioredoxin sequence. MutS protein was expressed with high level after IPTG induction using the strain E. coli AD494(DE3). SDS-PAGE revealed that the expected protein with a molecular weight of 108 kD which is about 35% of the total bacterial proteins is almost soluble. The expected protein was purified directly by immobilized metal (Ni2+) chelation affinity chromatography and the purity is over 90%. MutS protein activity verified using mismatch DNA showed that the expression product can recognize and bind to base-pair mismatch specifically.

Objective: To investigate the pathogenesis of Wilson's disease(WD)., Methods: Hepatocytes were isolated from WD patients' bioptic hepatic samples and cultured in vitro; WD proteins, the gene putative encoded products, were detected by SDS-PAGE in conjunction with Western blotting in liver samples of three patients and two controls. Their genomic DNAs were analyzed by means of direct DNA sequencing of WD gene (ATP7B) on exon 8., Results: The WD proteins lanes from two WD patients were found to be much weaker than that from the control, from which one WD patient was proven as heterozygote of 778 position CGG-->CTG(Arg778Leu) and 770 position CTC-->CTG change of ATP7B., Conclusion: WD is highly heterogeneous in clinical manifestations and inheritance pattern. Abnormally expressed putative WD proteins in WD patients might be the results of ATP7B mutations, and the study of ATP7B products would help to probe into the pathogenesis of WD.