Abstract:
Synthesis of enantiopure cis-α-irone from a renewable carbon source Disclosed herein are natural and synthetic enzymes capable of performing a method of producing cis-α-irone. The method comprises providing an enzyme capable of converting psi-ionone to cis-α-irone; and contacting the enzyme and psi-ionone under suitable conditions to produce cis-α-irone. The enzyme may be a methyltransferase from Streptomyces albireticuli (SaMT), a promiscuous bifunctional methyltransferase/cyclase (pMT1) enzyme from Streptomyces, or a modified pMT1 enzyme with at least one substitution. The enzymes allow the in-vivo and in-vitro production of cis-α-irone including the use of glucose as feedstock for the biotransformation into cis-α-irone.
Abstract:
A compound enzyme, comprising L-histidine methylase, halogen methyltransferase and trimethylhistidine sulfurylase. L-histidine is catalyzed by L-histidine methylase and halogen methyltransferase to obtain trimethylhistidine, and then is catalyzed by trimethylhistidine sulfurase to obtain the L-ergothioneine. The method can realize conversion from L-histidine to L-ergothioneine only in two steps. Moreover, SAM enzyme is regenerated, such that the usage amount of the SAM enzyme is greatly reduced. Therefore, the method greatly reduces the raw material cost. Moreover, the method is high in reaction concentration (about 30 g/L), simple in process and good in industrial production prospect.
Abstract:
The invention relates to methods and kits for identifying individuals at risk of thiopurine drug intolerance based on detecting the presence of mutations in the TPMT gene promoter associated with thiopurine drug resistance or intolerance.
Abstract:
Mutants of thiopurine S-methyltransferase (TPMT) are described. TPMTA mutant has a point mutation at cDNA position 238 (G.sup.238 .fwdarw.C), and TPMTB involves two nucleotide transitions at cDNA positions 460 (G.sup.460 .fwdarw.A) and 719 (A.sup.719 .fwdarw.G). TPMTB is the predominant mutant allele associated with human TPMT-deficiency which can cause potentially fatal toxicity when patients are treated with mercaptopurine, azathioprine, or thioguanine. The mutant alleles as well as PCR fragments, mutant proteins and antibodies therefor, together with kits and methods for assaying the TPMT genotype of individual patients are disclosed.