Determination of protein 3-dimensional structure offers very important information in biology researches, especially for understanding protein functions and redundant drug design. The X-ray crystallography is still the main technique for protein structure determination. Obtaining protein crystals is an essential procedure after protein purification in this technique. However, there is only 42% of soluble purified proteins yield crystals by statistics. Experimental verification of protein crystallizability is relatively expensive and time-consuming. Thus it is desired to predict the protein crystallizability by a computational method before starting the experiment. In this paper, combined with our own efforts, some successful in silico methods to predict the protein crystallizability are reviewed.
Crystallization ; methods ; Crystallography, X-Ray ; Protein Structure, Tertiary ; Proteins ; chemistry

AIM To observe the clinical efficacy of Huazhi Rougan Granules (Artemisiae scopariae Herba,Cassiae Semen,Rhei Radix et Rhizoma,etc.) in the treatment of damp-heat accumulation type non-alcoholic steatohepatitis (NASH) and its influence on insulin resistance.METHODS During January 2014-January 2016,a total of one hundred and twenty patients with damp-heat accumulation type NASH,given diet and exercise guidance,were randomly and equally divided into control group (polyene phosphatidylcholine) and treatment group (Huazhi Rougan Granules),administrated for twelve weeks.The levels of serum alanine aminotransferase (ALT),aspartate aminotranferase (AST),gamma-glutamyltransferase (GGT),total cholesterol (TC),triglyceride (TG),γ-glutamyl transpeptadase (GGT),fasting plasma glucose (FPG),fasting insulin (FINS),HOMA-IR index,adiponectin (ADPN) and leptin,body mass index (BMI) and uhrasound examination were detected before and after the treatment,respectively.These data were compared in two groups.RESULTS Compared with the control group,the serum ALT,AST,GGT,TC,TG,FPG,FINS and HOMA-IR of the patients in the treatment group decreased significantly,and liver fat were effectively reduced,while serum adiponectin increased markedly (P ＜ 0.05).After the treatment,remarkable reductions in the levels of BMI,leptin were observed in both groups (P ＜ 0.05).CONCLUSION Huazhi Rougan Granules combined with lifestyle modulation can effectively improve the syndrome of damp-heat accumulation type NASH by lowing insulin resistance.

Objective To investigate the effects of 17-methoxyl-7-hydroxy-benzene-furabcgakcone( MHBFC ) on isoproterenol-induced ventricular remodeling in mice. Methods Isoproterenol(ISO)was given subcutaneously(1 mg·kg-1, twice per day for 7 d)to induce ventricular remodeling in mice. Mice were divided into normal control group,model group, captopril group,MHBFC low and high-dose groups. 65 mg·kg-1 captopril was given by intragastric administration in captopril group,2. 5,5. 0 mg·kg-1 MHBFC were given by intravenous injection in MHBFC low and high-dose groups. At the end of the 7th day,the hearts of the mice were weighted,and myocardial hypertrophy index was expressed as heart weight/body weight, double kidneys weight/body weight and lung weight/body weight( HW/BW,KW/BW and LW/BW). Colorimetric method was used to determine the content of hydroxyproline( Hyp)in heart,the activity of superoxide dismutase( SOD)and the content of malondialdehyde( MDA)in serum. The histological changes were observed by HE and Masson’s staining,the changes of cross section area( CSA),collagen volume fraction,( CVF)and perivascular circumferential collagen area( PVCA)were determined. Results Compared with the model group,MHBFC potently inhibited cardiomyocyte hypertrophy,decreased the HW/BW, KW/BW and LW/BW,improved cardiac pathology changed,increased the of activity SOD,decreased the content of MDA in serum and the content of Hyp in heart tissue(P﹤0. 01 or P﹤0. 05),decreased the CVF and PVCA(P﹤0. 01). Conclusion MHBFC possesses protective effects against ISO-induced ventricular remodeling in mice,which may be related to its actions in reducing the oxidative stress and improving the antioxidant activity of the body.

AIM: To observe the effects of herba houttuyniae injection, a chinese medicine, on myocardial injury induced by endotoxin and to explore the possible mechanism. METHODS: 24 male SD rats,weghting (250?30) g, were randomly divided into three groups: normal control group(NC, n=6), endotoxin group (ET, n=6), herba houttuyniae injection puls endotoxin group (HHI+ET, n=6) and herba houttuyniae injection group (HHI, n=6). Heart was isolated from rats and perfused on Langendorff apparatus with Krebs-Henseleit (KH) buffer (Saturation 95%+5%CO_2) at a constant pressure (8.33 kPa) and temperture(37℃). The activities of superoxide dismutase (SOD) and malondialdehyde (MDA) content of efflux from coronary artery were measured at certain time points (0 min, 20 min, 50 min, 80 min). The ventricular function, the concentration of nitric oxide (NO) and the activity of succinate dehydrogenase (SDH) in myocardial tissue were also observed. RESULTS: Compared with ET group, the percentage recovery of the product of left ventricular pressure difference and heart rate [(LVSP-LVEDP)?HR], LVDP,+dp/dt_(max) were all increased apparently in HHI treatment group. The activities of SOD, SDH and the concentration of MDA, NO in HHI treatment group were close to that in normal control group. CONCLUSION: Herba houttuyniae injection protects myocardium against injury induced by endotoxin. It may be related to decrease in the level of NO, the strength of antioxidation, the stability of enzyme activities and the improvement of energy metabolism in myocardium.

AIM: To observe the protective effect of non-wounded ischemic preconditioning on ischemic/reperfusion injury in isolated rat hearts. METHODS: 25 male SD rats, weighting (250?30) g, were randomly divided into three groups: control group (C, n= 8), anoxia/reoxygenation group (A, n= 8) and non-wounded legs ischemic preconditioning group (N-WIP, n= 9).Hearts were isolated from rats and perfused on a Langendorff apparatus with a normal Krebs-Henseleit buffer (saturation 95% O 2+5% CO 2) at a constant pressure (8.33 kPa) and temperature (37 ℃) in C group ; Following 15 min equilibration, hearts were subjected to 15 min of global ischemia and 15 min reperfusion (37℃) in A group ; Rats were subjected to non-wounded leg repeated-brief ischemic preconditioning, and then treated in procedure similar to A group in N-WIP group.The activities of superoxide dismutase (SOD) and Ca 2+ -Mg 2+ -ATPase, malondialdehyde (MDA) content of efflux from coronary vessel and myocardium, myocardium monophasic action potential and contractile force were measured before ischemia, 15 minutes after ischemia and 5, 15 minutes after reperfusion. RESULTS: Compared with A group, non-wounded legs ischemic preconditioning reduced the incidence of reperfusion arrhythmias ( P

Aim To observe the protective effect of glycine from myocardial cell injury of the isolated rat heart induced by endotoxin. Methods 21 male SD rats,weghting(250?30)g,were randomly divided into three groups:control group(n=7),endotoxin group(n=7),glycine/endotoxin group(n=7).Heart were isolated from the rats and perfused on Langendorff apparatus with Krebs-Henseleit(KH)buffer(Saturation 95%+5% CO_2)at a constant pressure(8.33 kPa)and temperture(37℃). The activities of lactate dehydrogenase(LDH),creatine kinase(CK),superoxide dismutase(SOD) and the level of malondialdehyde (MDA) of efflux from coronary artery, monophasic action potential(MAP)were determined at the certain time(0,20,50,80 min). Results Monophasic action potential were markedly improved in Gly/ET group. Glycine can attenuate the release of LDH,CK from myocardial cell. The activity of SOD and the level of MDA were close to control group. Conclusion Glycine can protect myocardial cells of the isolated rat heart from the damage induced by endotoxin.

Objective To study human bocavirus (HBoV) induced respiratory tract infection in Guangdong Province in China. Methods HBoV was deteced by using polymerase chain reaction (PCR) technology and was identified by DNA sequences. Results One strain of HBoV was detected and identified from 50 samples collected from children with acute respiratory tract infections. This was the first clinical case of HBoV infection reported in Guangdong and was named as GD-1 strain. The HBoV capsid protein (VP) gene amplified from the specimen by PCR was identified by sequencing and was compared with gene sequences in GenBank. Phylogenetic trees were constructed for sequence homology analysis. The nucleotides similarities between GD-1 and Beijing strains, France strains and Canada strains were over 98%, while the simlilarity was over 36% compared with Korea KNIH-2K6GJ2713 strain and over 77% compared with US NH4549 strain. Conclusion HBoV infection does exist in Guangdong Province. It is valuable to start systemic study on it.

We report a case of maternal asymptomatic COVID-19 in a patient with typical CT image of pneumonia in the third trimester, and both the mother and baby were well. The patient, a 30-year-old female, was transferred to Yichun People's Hospital at 37 +3 gestational weeks because of a positive 2019 novel coronavirus nucleic acid result over seven hours. Her husband and mother-in-law were diagnosed with COVID-19 eight days before her admission and on the same day, respectively. The patient reported no discomfort before admission, and there were no abnormalities in the prenatal course during her pregnancy. On February 13 (the second day of admission), a patchy blurred shadow was observed in the lower lobe of the right lung in chest CT scan, and a live baby girl was delivered by a precaution-based emergent cesarean section because of suspected fetal distress shown in electrical fetal heart monitoring. Both the mother and the newborn were isolated separately after the operation without etiological examination of amniotic fluid, umbilical cord blood, placenta, etc. All the medical staff involved in the cesarean section were isolated as well. The mother was healthy and remained asymptomatic after delivery, while antiviral and anti-inflammatory treatment was offered. COVID-19 nucleic acid tests of pharyngeal swab were negative on the 4 th and 6 th day after operation. Chest CT on the 5 th day after delivery showed inflammation in the lower lobe of the right lung, and reexamination on the 8 th day showed a slight absorption of the inflammation. Samples of peripheral blood and pharynx swab were obtained from the newborn on the day of birth and four and seven days after birth and novel coronavirus nucleic acid test were all negative. The mother and baby dyad were discharged nine days after operation. And novel coronavirus nucleic acid tests were all negative in all medical staff involved.