Thermostability can be increased by introducing prolines at suitable sites in target proteins. Two single (G138P, G247D) mutants and one double (G138P/G247D) mutant of xylose isomerase from Streptomyces diastaticus No.7, strain M1033 have been constructed by site-directed mutagenesis. With respect to the wild-type enzyme, G138P showed about a 100% increase in thermostability, and G247D showed an increased catalytic activity. Significantly, the double mutant, G138P/G247D displayed even higher activity than G247D and better heat stability than G138P. Its half life was about 2.5-fold greater than the wild-type enzyme, using xylose as a substrate. Molecular modelling suggested that the introduction of a proline residue in the turn of a random coil may cause the surrounding conformation to be tightened by reducing the backbone flexibility. The change in thermostability can, therefore, be explained based on changes in the molecular rigidity. Furthermore, the improvements in the properties of the double mutant indicated that the advantages of two single mutants can be combined effectively.

Regulator of G protein signaling 3 (RGS3) is a negative regulator of G protein-mediated signaling. RGS3 has previously been shown to be expressed among various cell types within the mature heart. Basic and clinical studies have reported abnormal expressions of RGS3 in hypertrophic hearts and in the failing myocardium. However, the role of RGS3 in cardiac remodeling remains unclear. In this study, we investigated the effect of cardiac overexpression of human RGS3 on cardiac hypertrophy induced by aortic banding (AB) in RGS3 transgenic mice and wild-type littermates. The extent of cardiac hypertrophy was evaluated by echocardiography as well as pathological and molecular analyses of heart samples. RGS3 overexpression in the heart markedly reduced the extent of cardiac hypertrophy, fibrosis, and left ventricular dysfunction in response to AB. These beneficial effects were associated with the inhibition of MEK-ERK1/2 signaling. In vitro studies performed in cultured neonatal rat cardiomyocytes confirmed that RGS3 overexpression inhibits hypertrophic growth induced by angiotensin II, which was associated with the attenuation of MEK-ERK1/2 signaling. Therefore, cardiac overexpression of RGS3 inhibits maladaptive hypertrophy and fibrosis and improves cardiac function by blocking MEK-ERK1/2 signaling.

These results imply a role for CARD3 as a positive regulator of intestinal epithelial cell apoptosis in the inflamed colon. Genetic loss of CARD3 is protective against colitis through decreased epithelial cell apoptosis and consequent enhancement of intestinal epithelial barrier function. Thus, targeted CARD3 inhibition may represent a new therapeutic approach in IBD.

The Bullfrog Lithobates catesbeianus is a species of economic important edible frog and often chosen as experimental animal model. Although, some studies in the literatures have reported the parameters of hematology and serum biochemistry in several Rana species, a comprehensive profile of hematology and biochemistry in farmed bullfrogs was very limited, especially during the hibernating period. 140 apparently healthy farmed bullfrogs (70 males and 70 females) were used during the active and hibernating periods to determine the hematology and serum biochemistry parameters including morphometry of erythrocytes, PCV, HGB, MCV, MCH, MCHC, RBC count, WBC count, differential leukocyte count, glucose (Glu), triglycerides (TG), cholesterol (Cho), blood urea nitrogen (Bun), uric acid (UA), creatine (Cre), total protein (TP), albumin (Alb), globulin (Glo), γ-glutam (GGT), total bilirubin (TB), alkaline phosphatase (Alp), a-amylase (Amy), CK, AST, ALT, LDH, K, Na, Cl and nCa (that is, the ionized calcium level when pH=7.4). Differences between sexes showed that male bullfrogs possessed a statistically higher LDH activity level, and statistically lower levels of Cre, Na and Ca concentrations. Additionally, it was noted that bullfrogs during the active period had significantly lower values for HGB, PCV, MCV, ALT, Glo, Bun, Na, Cl and surface areas and volumes of RBCs and their nuclei, and significantly higher values for WBCs counts and Cre than the hibernating ones. These baseline data could be used for health monitoring and disease diagnostics in bullfrogs artificial farming and serve as general reference values for future studies on the physiology of this species.