496-65-1Relevant articles and documents
Substrate recognition by β-ketoacyl-ACP synthases
Borgaro, Janine G.,Chang, Andrew,MacHutta, Carl A.,Zhang, Xujie,Tonge, Peter J.
, p. 10678 - 10686 (2011)
β-Ketoacyl-ACP synthase (KAS) enzymes catalyze Claisen condensation reactions in the fatty acid biosynthesis pathway. These reactions follow a ping-pong mechanism in which a donor substrate acylates the active site cysteine residue after which the acyl group is condensed with the malonyl-ACP acceptor substrate to form a β-ketoacyl-ACP. In the priming KASIII enzymes the donor substrate is an acyl-CoA while in the elongating KASI and KASII enzymes the donor is an acyl-ACP. Although the KASIII enzyme in Escherichia coli (ecFabH) is essential, the corresponding enzyme in Mycobacterium tuberculosis (mtFabH) is not, suggesting that the KASI or II enzyme in M. tuberculosis (KasA or KasB, respectively) must be able to accept a CoA donor substrate. Since KasA is essential, the substrate specificity of this KASI enzyme has been explored using substrates based on phosphopantetheine, CoA, ACP, and AcpM peptide mimics. This analysis has been extended to the KASI and KASII enzymes from E. coli (ecFabB and ecFabF) where we show that a 14-residue malonyl-phosphopantetheine peptide can efficiently replace malonyl-ecACP as the acceptor substrate in the ecFabF reaction. While ecFabF is able to catalyze the condensation reaction when CoA is the carrier for both substrates, the KASI enzymes ecFabB and KasA have an absolute requirement for an ACP substrate as the acyl donor. Provided that this requirement is met, variation in the acceptor carrier substrate has little impact on the kcat/Km for the KASI reaction. For the KASI enzymes we propose that the binding of ecACP (AcpM) results in a conformational change that leads to an open form of the enzyme to which the malonyl acceptor substrate binds. Finally, the substrate inhibition observed when palmitoyl-CoA is the donor substrate for the KasA reaction has implications for the importance of mtFabH in the mycobacterial FASII pathway.
Synthesis of H4 pantetheine adducts for histone acetyltransferase inhibition
Wu, Jiang,Zheng, Yujun George
, p. 231 - 234 (2010)
Site-specific modifications of peptides provide a powerful tool for design of chemical probes and enzyme inhibitors. A convenient synthesis method was developed and used to produce H4K16-pantetheine bisubstrate analogs which could be employed as inhibitors of histone acetyltransferases in vivo and in vitro.
Gatekeeping Ketosynthases Dictate Initiation of Assembly Line Biosynthesis of Pyrrolic Polyketides
Yi, Dongqi,Acharya, Atanu,Gumbart, James C.,Gutekunst, Will R.,Agarwal, Vinayak
supporting information, p. 7617 - 7622 (2021/05/26)
Assembly line biosynthesis of polyketide natural products involves checkpoints where identities of thiotemplated intermediates are verified before polyketide extension reactions are allowed to proceed. Determining what these checkpoints are and how they operate is critical for reprogramming polyketide assembly lines. Here we demonstrate that ketosynthase (KS) domains can perform this gatekeeping role. By comparing the substrate specificities for polyketide synthases that extend pyrrolyl and halogenated pyrrolyl substrates, we find that KS domains that need to differentiate between these two substrates exercise high selectivity. We additionally find that amino acid residues in the KS active site facilitate this selectivity and that these residues are amenable to rational engineering. On the other hand, KS domains that do not need to make selectivity decisions in their native physiological context are substrate-promiscuous. We also provide evidence that delivery of substrates to polyketide synthases by non-native carrier proteins is accompanied by reduced biosynthetic efficiency.
Mechanistic Studies on CysS - A Vitamin B12-Dependent Radical SAM Methyltransferase Involved in the Biosynthesis of the tert-Butyl Group of Cystobactamid
Begley, Tadhg P.,Wang, Yuanyou
supporting information, p. 9944 - 9954 (2020/07/08)
Cobalamin (Cbl)-dependent radical S-adenosylmethionine (SAM) methyltransferases catalyze methylation reactions at non-nucleophilic centers in a wide range of substrates. CysS is a Cbl-dependent radical SAM methyltransferase involved in cystobactamid biosynthesis. This enzyme catalyzes the sequential methylation of a methoxy group to form ethoxy, i-propoxy, s-butoxy, and t-butoxy groups on a p-aminobenzoate peptidyl carrier protein thioester intermediate. This biosynthetic strategy enables the host myxobacterium to biosynthesize a combinatorial antibiotic library of 25 cystobactamid analogues. In this Article, we describe three experiments to elucidate how CysS uses Cbl, SAM, and a [4Fe-4S] cluster to catalyze iterative methylation reactions: a cyclopropylcarbinyl rearrangement was used to trap the substrate radical and to estimate the rate of the radical substitution reaction involved in the methyl transfer; a bromoethoxy analogue was used to explore the active site topography; and deuterium isotope effects on the hydrogen atom abstraction by the adenosyl radical were used to investigate the kinetic significance of the hydrogen atom abstraction. On the basis of these experiments, a revised mechanism for CysS is proposed.
COMPOSITION FOR PROMOTING HAIR GROWTH CONTAINING NOVEL PANTETHEINE DERIVATIVE
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Paragraph 0060, (2018/07/29)
Provided is a composition for promoting hair growth, containing, as an active ingredient, a new compound represented by the following formula 1 or a salt thereof, which exhibits an excellent effect of promoting the growth of dermal papilla cells to thereby exhibit the effect of promoting hair growth: wherein R is any one selected from the group consisting of 2-methylbutyryl, 3-methylbutyryl, cinnamoyl, 4-pentenoyl, 10-undecenoyl, isobutyl formate, 2,4-dihydroxybenzoyl, geranyl, farnesyl, acryloyl, propanone, 2-pentanone, 1-(4-hydroxyphenyl)ethanone, 1-(2,4-dihydroxyphenyl)ethanone, pentanoic acid, 2-hydroxypropanoic acid, 2-phenylacetic acid, 2-(4-(propanoyl)phenyl)acetic acid, 4-methylbenzoic acid, 4-(4-phenyl)-4-oxobutanoic acid, 2-oxoethyl acetyl, 2-phenoxyacetyl, 2-(benzyloxy)acetyl, 4-methoxybenzoyl, 3,5-dimethylphenol, 6-methoxybenzene-1,4-diol, propenylbenzene, and 4-hydroxycoumarin.
