Resveratrol is a natural phytoalexin with special pharmacological and health functions. Stilbene synthase (STS) is a key and rate-limiting enzyme in the biosynthesis of resveratrol that is present only in a limited number of plants. The content of resveratrol from Polygonum cuspidatum is more than 1000 times higher than grapes and peanuts. We speculate that the catalytic ability of different STS may be one of the reasons causing differences in the content of resveratrol. To verify the above speculation, Vitis vinifera stilbene synthase gene (VvSTS) was amplified according to overlap PCR protocol with genomic DNA as template. VvSTS and PcSTS (PcPKS5) were analyzed through heterologous expression in Escherichia coli. The expression products were purified with Ni-NTA sepharose affinity chromatography and desalted through PD-10 column. The molecular weight of the two fusion proteins was about 43 kDa. Enzyme reaction and product analysis showed that the two products were resveratrol. The enzyme kinetic analysis showed that the catalyze efficiency (Kcat/Km) of PcPKS5 was 2.4 times of the VvSTS. Our findings confirms that STS from certain plants has much higher catalytic capability.
Acyltransferases ; metabolism ; Fallopia japonica ; enzymology ; Recombinant Fusion Proteins ; biosynthesis ; Stilbenes ; metabolism ; Vitis ; enzymology

Objective To investigate the epidemiological information of patients in pre-hospital medical care for our large and medium-sized cities and probe the patients' characteristic. Method The data in 2008 were exported from the computer databases of 8 large and medium-sized cities' emergency medical centers in our country.The thorough records of data were conducted to statistical analysis. Results ( 1 ) The scheduling time, running time, rescue time, returning time, total time and service radius in the pre-hospital medical care group were 2.16± 1.10(min), 14.01 ±6.82(min), 12.12±5.96(min), 14.08± 6.85(min), 42.34± 20.21(min)and 8.50±4.18(km), and the above parameter in the non-death group were 2.19 ± 1.13(min), 14.15 ± 7.14(min),11.60±6.72(min), 14.92 ±6.89(min), 41.86± 19.53(minutes) and 8.63±4.31(Km), and the above parameter in the death group were 2.10± 1.08(min), 13.68 ± 7.14(min), 25.25 ± 12.34(min), 13.75±6.48(min), 54.74 ± 25.47(min) and 7.86± 3.91(Km), and the above parameter in the non-sudden cardiac death group were2.09± 1.03(min), 13.58±6.78(min), 25.53± 12.34(min), 13.60± 6.54(min), 53.79±23.77(min) and 7.67 ± 3.86(Km), and the above parameter in the sudden cardiac death group were 2.12 ±1.02(min), 14.10±7.05(min), 24.79± 12.08(min), 13.79±6.61(min), 54. 80 ± 25. 36( min) and 7.90±3.92(Km) respectively. The scheduling time, running time, returning time and service radius in the death group were less than those of the non-death group, but the rescue time and total time of the former were more than those of the latter respectively ( P ＜ 0.05 or P ＜ 0. 001 ). The scheduling time and returning time didn' t have significant difference between the sudden cardiac death group and the non-sudden cardiac death group respectively ( P ＞ 0.05), but the running time, total time and service radius of the sudden cardiac death group were more than those of the non-sudden cardiac death group, and the rescue time of the former was less than that of the latter respectively ( P ＜ 0.05 or P ＜ 0.001 ). (2)The patients' amount in pre-hospital medical care group, the non-death group, the death group, the non-sudden cardiac death group and the sudden cardiac death group were at most in first quarter, and the least time slice of patients' amount were 4:00～ 6:00, 4:00～6:00, 4:00～ 6:00, 22:00～ 24:00, 2:00～4:00 respectively, and the most time slice of patients' amount were 20:00～ 22:00, 20:00～22:00, 8:00～ 10:00, 2:00 ～ 4:00, 8:00 ～ 10:00 respectively. (3)In 241 876 cases of pre-hospital medical care group, the patients' amount of trauma was at most, whose age grades was by far among21 ～50, and the others in sequence were nervous system, circulatory system, other group, digestive system, respiratory system and poisoning group respectively, whose age grades in nervous system, circulatory system and respiratory system was by far above 51, especially above 70. The patients' age grades in other group and digestive system had two climax age groups, which the one was 21 ～ 30, and the other was above 70. The patients' age grades in poisoning group was by far among 21 ～ 50, which the patients' amount of acute alcoholism was at the most. (4) In 12 568 cases of death group, the death amount of circulatory system, other group, respiratory system, nervous system and digestive system ranked at the lst,2nd,4th,5th 8th respectively, whose age grades was by far above 51, especially above 70,and the patients' amount of sudden cardiac death was at the most in the death amount of circulatory system. The death amount of trauma and poisoning group ranked at the 3rd, 6th respectively, whose age grades was by far among 21 ～ 50. (5)The total amount, the death amount and the sudden cardiac death amount of male patients were more than those of female patients. (6)The percentage of the death group to the pre-hospital medical care group was 5.20%, and the percentage of the sudden cardiac death group to the pre-hospital medical care group was 1.29%,and the percentage of the sudden cardiac death group to the death group was 24.87 %, and the percentage of the sudden cardiac death group to the circulatory system group was 67.33 %. Conclusions ( 1 )The trauma and the sudden cardiac death are the overriding reason of disease and the overriding reason of death in our large and medium-sized cities respectively. (2) It is very important to cut the death rate of the middle-old age patients by strengthening prevention and cure of cardiovascular and cerebrovascular diseases, discerning the critical illness early and improving the level of pre-hospital medical care. (3)It is a strong method to decrease the total amount and the death amount of the trauma, especially in traffic accident, by strengthening safety in production, observing traffic regulation and enhancing the legal awareness.