RESUMEN
Structural biology research of terpene synthases (TSs) has provided a useful basis to understand their catalytic mechanisms in producing diverse terpene products with polycyclic ring systems and multiple chiral centers. However, compared to the large numbers of>95,000 terpenoids discovered to date, few structures of TSs have been solved and the understanding of their catalytic mechanisms is lagging. We here (i) introduce the basic catalytic logic, the structural architectures, and the metal-binding conserved motifs of TSs; (ii) provide detailed experimental procedures, in gene cloning and plasmid construction, protein purification, crystallization, X-ray diffraction data collection and structural elucidation, for structural biology research of TSs; and (iii) discuss the prospects of structure-based engineering and de novo design of TSs in generating valuable terpene molecules, which cannot be easily achieved by chemical synthesis.
Asunto(s)
Transferasas Alquil y Aril , Transferasas Alquil y Aril/química , Transferasas Alquil y Aril/metabolismo , Transferasas Alquil y Aril/genética , Cristalografía por Rayos X/métodos , Terpenos/metabolismo , Terpenos/química , Clonación Molecular/métodos , Modelos Moleculares , Conformación ProteicaRESUMEN
BACKGROUND: Kawasaki disease affects mainly children younger than five years, leading to coronary artery lesions, even to life-threatening myocardial infarctions. Since 1976, Kawasaki disease has occurred in thousands of children in Taiwan; some of them died. METHODS: Questionnaire forms for the survey of epidemiological features of Kawasaki disease were designed and sent to the hospitals of 100 or more beds in Taiwan, in 1987, 1992, 1994, and 2001, for retrospective reviews of their patients with Kawasaki disease encountered during 1976-2000. A school-based mass survey, on the prevalence of children with history of Kawasaki disease was conducted every year from 1990 to 2000. RESULTS: Since 1976, the number of Kawasaki disease patients increased, totaling to 8,267 patients in 2000. The ratio of the incidence increased by 1.15 times annually (Poisson regression), reaching the highest incidence of 54.9 per 100,000 children <5 years of age in 1998. Of them, 85.1% were under 5 years of age. The male-to-female ratio was 1.6. Coronary artery lesions were noted during acute, subacute and convalescent stages in 25.8% of the patients. The fatality rate decreased from 0.4% to 0.06%. There was no student with history of Kawasaki disease among students surveyed in 1990. Subsequent school surveys showed the prevalence was 24.6 in 1991, 74.6 in 1996, then reached to 103.9 per 100,000 school children in 2000, with an annual increase of 1.24 times (Poisson regression). CONCLUSIONS: In Taiwan, Kawasaki disease, first diagnosed in 1976, continued to occur with several outbreaks reaching to a peak incidence of 54.9 per 100,000 population less than 5 years of age in 1998. Epidemiological features of Kawasaki disease in Taiwan were similar to the Japanese experiences and the incidence was, next only to Japan, the second highest in the world.