A themostable intracellular β-galactosidase from a thermophilic Bacillus stearothermophilus was purified by a combination of (NH4)2SO4 fractionation, ion-exchange (DEAE-22)and gel filtration (Sephades G-75). The optimum temperature and pH of the enzyme acivity were 60Cand pH6.4 respectively. The β-galatosidase activity exhibited thermosttability at 50 C. The enzyme was significaantly activated by alkali and alkali-earth metal ions. The activity was inhibited by Zn2+ 、 Fe3+ 、 Cu2+Reducing agents enhanced β- galactosidase activity. Thiol-binding agents drastically decreased the enzyme activity. The enzyme was specific for β-D glycosidic linkages,and the identity of the aglycone moiety also influenced enzyme activity. At 55Cthe Km for O-nitrophenyl-β-D-galactosidase (ONPG)and lactose were 2. 63mmol/L and 4.39mmol/L, respectively,and Vmax for both substrates were 1.93 × 10-5mmol. min-1 mg-1protein6.54 ×105 mmol. min-1. mg-1protein,respectively. The enzyme was inhibited by glucose (the products of lactose hydrolysis,ki 2.47mmol/L),but not by galactose. In addition,the enzyme possessed transgalactosylation activity. Galacto-oligosaccharides,both tri- and tetrasaccharide,were involved in the products during lactose hydrolysi

A themostable intracellular ? galactosidase from a thermophilic Bacillus stearothermophilus was purified by a combination of (NH 4) 2SO 4 fractionation,ion exchange (DEAE 22)and gel filtration (Sephades G 75).The optimum temperature and pH of the enzyme acivity were 60℃and pH6.4 respectively.The ? galatosidase activity exhibited thermosttability at 50 ℃.The enzyme was significaantly activated by alkali and alkali earth metal ions.The activity was inhibited by Zn 2+ 、 Fe 3+ 、 Cu 2+ Reducing agents enhanced ? galactosidase activity.Thiol binding agents drastically decreased the enzyme activity.The enzyme was specific for ? D glycosidic linkages,and the identity of the aglycone moiety also influenced enzyme activity.At 55℃the Km for O nitrophenyl ? D galactosidase(ONPG)and lactose were 2.63mmol/L and 4.39mmol/L, respectively,and Vmax for both substrates were 1.93?10 5 mmol.min 1 .mg 1 protein6.54?10 5 mmol.min 1 .mg 1 protein,respectively.The enzyme was inhibited by glucose (the products of lactose hydrolysis,ki 2.47mmol/L),but not by galactose.In addition,the enzyme possessed transgalactosylation activity.Galacto oligosaccharides,both tri and tetrasaccharide,were involved in the products during lactose hydrolysis.

AIM:To determine which species of snake venoms contained protein c activator among 9 species of Chinese snake venoms. METHODS: Anticoagulant activity was examined by activated partial thromboplastin time (APTT) assay,and amidolytic activity was measured with activated protein c (APC) specific chromogenic peptide substrate-chromozy APC. RESULTS: Among 9 species of Chinese snake venoms,Trimeresurus mucrosquamatus venom and Agkistrodon halys venom were not only able to generate amidolytic activity from purified human PC, but also prolonged APTT strongly even at such a concentration as 1.5 mg/L.CONCLUSION: Trimeresurus mucrosquamatus venom and Agkistrodon halys venom contain protein c activator which activating human plasma PC into APC.

AIM:To determine which species of snake venoms contained protein c activator among 9 species of Chinese snake venoms. METHODS: Anticoagulant activity was examined by activated partial thromboplastin time (APTT) assay，and amidolytic activity was measured with activated protein c (APC) specific chromogenic peptide substrate-chromozy APC. RESULTS: Among 9 species of Chinese snake venoms，Trimeresurus mucrosquamatus venom and Agkistrodon halys venom were not only able to generate amidolytic activity from purified human PC, but also prolonged APTT strongly even at such a concentration as 1.5 mg/L.CONCLUSION: Trimeresurus mucrosquamatus venom and Agkistrodon halys venom contain protein c activator which activating human plasma PC into APC.

Objective　To clarify the role of sexual related Y (SRY) gene detection in the diagnosis of gonadal dysgenesis. Methods　Sixteen cases of gonadal dysgenesis were included in this study: 5 with androgen insensitivity syndrome, 1 with 17-α-hydroxylase deficiency, 4 with true hermaphrodite, 2 with 45,X/46,XY gonadal dysgenesis, 1 with 45,X gonadal dysgenesis, 1 with XY pure gonadal dysgenesis, 1 with testicular regression, and 1 XY female who gave birth to a normal baby. SRY gene was detected by using polymerase chain reaction (PCR) in blood and gonad samples and by direct sequencing of the SRY motif. Results　Among the 16 cases, 15 were blood SRY positive, among which 13 (86.7%) showed the presence of testicular tissue, and 2 showed ovaries without testicular tissue. One SRY negative case showed the presence of testicular tissue. In 3 cases, SRY detection in gonadal tissue correlated with pathological findings but not with blood karyotype. The correlation between peripheral blood SRY and the pathology of the gonads was 81.25% and the correlation between the presence of peripheral blood Y chromosome and pathology of the gonads was 68.75%. Sequencing of the SRY motif in an XY female who gave birth to a normal baby showed no mutation. Conclusions　SRY detection is more sensitive and specific than blood karyotype in the prediction of the presence of testicular tissue. Peripheral blood karyotype does not necessarily reflect gonadal type. There may be testicular related factors other than the SRY gene.

Acylcarnitines are metabolic intermediates of fatty acids and branched-chain amino acids having vital biofunctions and pathophysiological significances.Here,we developed a high-throughput method for quantifying hundreds of acylcarnitines in one run using ultrahigh performance liquid chromatography and tandem mass spectrometry(UPLC-MS/MS).This enabled simultaneous quantification of 1136 acyl-carnitines(C0-C26)within 10-min with good sensitivity(limit of detection＜0.7 fmol),linearity(cor-relation coefficient＞0.992),accuracy(relative error＜20％),precision(coefficient of variation(CV),CV＜15％),stability(CV＜15％),and inter-technician consistency(CV＜20％,n=6).We also established a quantitative structure-retention relationship(goodness of fit＞0.998)for predicting retention time(tR)of acylcarnitines with no standards and built a database of their multiple reaction monitoring parameters(tR,ion-pairs,and collision energy).Furthermore,we quantified 514 acylcarnitines in human plasma and urine,mouse kidney,liver,heart,lung,and muscle.This provides a rapid method for quantifying acyl-carnitines in multiple biological matrices.