Background: In Moco biosynthesis, sulfur is transferred from L-cysteine to MPT synthase, catalyzing the conversion of cPMP to MPT. Results: The rhodanese-like protein YnjE is a novel protein involved in Moco biosynthesis. Conclusion: YnjE enhances the rate of conversion of cPMP to MPT and interacts with MoeB and IscS. Significance: To understand the mechanism of sulfur transfer and the role of rhodaneses in the cell.
Goniothalamus species (Annonaceae) is a shrub that grows in the rainforest of tropical Asia. Several compounds have been isolated and exhibit the potential use for cancer treatment. In this work, altholactone isolated from Goniothalamus macrophyllus was investigated for its cytotoxicity, apoptosis signalling and the expression of cancer‐related genes in the cervical carcinoma HeLa cells. Cytotoxicity was evaluated by MTT assay. Apoptotic characteristics were evaluated by morphological studies. Caspase‐3 activity was detected using a fluorogenic substrate. Cytochrome c release from mitochondria and protein Bid were determined by Western blotting and cancer‐related genes expression by RT‐PCR. The results demonstrated that altholactone was cytotoxic to HeLa (IC50 = 9.6 μg/mL), and apoptotic cell death was manifested by appearance of chromatin condensation and caspase‐3 activation, which was inhibited by specific inhibitors of both caspase‐8 and ‐9. Release into the cytosol of cytochrome and cleavage of Bid occurred. Altholactone also caused a decrease in bcl‐2 and an increase in p53 expression. These unique properties of altholactone suggest a potential for cancer chemotherapy.
To characterize physiological stress response against simulated short-distance sprints among world-class paddlers. Thirteen dragon boat gold medalists performed 200-m and 500-m simulated race trials on a kayak ergometer in a randomized, counter-balanced, crossover fashion. During the 200-m and 500-m sprints, oxygen consumption (VO2) increased from 8.7 to 31.2 ml/kg/min and from 8.0 to 32.7 ml/kg/min within 60 s, respectively. A plateau of 35 ml/kg/min below maximal VO2(VO2max) (39.7 ± 6.3 ml/kg/min) was reached at 75 s during the 500-m sprint. Respiratory exchange ratio dropped from 1.21 ± 0.16 to 1.07 ± 0.12 and 1.28 ± 0.13 to 1.06 ± 0.16 at 45 s, and resurged to 1.17 and 1.28 at the end of 200-m and 500-m sprints with lactate concentration reached 13 ± 2 and 15 ± 2 mM. Aerobic energy contribution to paddling power increases from ~10% for the first 15 s to ~80% for the last 15 s during the 500-m trial. Postexercise plasma thiobarbituric acid reactive substances increased by 376% and 543% above baseline after 200-m and 500-m trials (P < 0.001, between trials), respectively, followed by quick returns to baseline in 30 min (P < 0.001). Increased plasma creatine kinase (+48%) was observed only after the 500-m trial (P < 0.001, between trials), not 200-m trial. Our data suggest that muscle damage occurred only when maximal sprinting exceeding 2 min, highlighting an importance of volume than intensity on exercise-induced muscle damage.
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