Studium biosyntetické dráhy antibiotika linkomycinu

Abstract

1. L.3'4-Dihydroxyphenyl a|anine.extraďo|cleavage cyclizationin lincomycin biosynthesis. is followed by intra-molecular The aim of the work gene,characterizeit better DOPA aromaticring is the lincomycinsynthesis. was to assignfunctionto the proteincodedfor by an lmbBl and confirm the assumptionthat2,3-extradiolfission of the actualreactioninvolvedin the metabolicpathwayleadingto fooH HrN-) aOH tyÍo8|n cooH cooH ,,"1 ,,"4 .Ť:+*.i'} 2'3.6ÓcoDoPA /t{3€Íboxy+ox}prcponý}2'34|hyÚ} 1/í pyÍrolc2€íboxy|lo rc|d Fig' 1 |nitia|steps of the amino acid subpathway oÍthe |incomycin biosynthesis The resultsof the feedingexperimentswith labeledintermediatesand subsequent NMR analysis(BRAHME etal., 1984),bearedwitnessof thefactthattheaminoacid sub- pathwayof thelíncomycinbiosynthesisincludes2,3-extradiolcleavageof DoPA (Fig. 1). Neusser and coworkers (NEUSSER et al., 1998) showed that LmbBl catalyzes conversionof DOPA to anunspecifiedyellowcompound. It appearedinapplicableto isolatethe LmbBl reactionproductdirectlyfrom in y,itroreacÍioncatalyzedby thepurifiedLmbBl partlyas LmbBl lost mostof its activity duringdialysis.mostprobablydue to oxidationof theferrousion proposedas a cofactor, andpartlydue to thefact thatmanydiÍ.ferentDoPA oxidationproductswereproducedin the system.Instead,a system simrlar to that applied Íbr...