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Selness SR, Boehm TL, Walker JK, Devadas B, Durley RC, Kurumbail R, Shieh H, Xing L, Hepperle M, Rucker PV, Jerome KD, Benson AG, Marrufo LD, Madsen HM, Hitchcock J, Owen TJ, Christie L, Promo MA, Hickory BS, Alvira E, Naing W, Blevis-Bal R, Devraj RV, Messing D, Schindler JF, Hirsch J, Saabye M, Bonar S, Webb E, Anderson G, Monahan JB. Design, synthesis and activity of a potent, selective series of N -aryl pyridinone inhibitors of p38 kinase. Bioorg Med Chem Lett 2011; 21:4059-65. [DOI: 10.1016/j.bmcl.2011.04.120] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 04/23/2011] [Accepted: 04/26/2011] [Indexed: 10/18/2022]
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2
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Selness SR, Devraj RV, Devadas B, Walker JK, Boehm TL, Durley RC, Shieh H, Xing L, Rucker PV, Jerome KD, Benson AG, Marrufo LD, Madsen HM, Hitchcock J, Owen TJ, Christie L, Promo MA, Hickory BS, Alvira E, Naing W, Blevis-Bal R, Messing D, Yang J, Mao MK, Yalamanchili G, Vonder Embse R, Hirsch J, Saabye M, Bonar S, Webb E, Anderson G, Monahan JB. Discovery of PH-797804, a highly selective and potent inhibitor of p38 MAP kinase. Bioorg Med Chem Lett 2011; 21:4066-71. [PMID: 21641211 DOI: 10.1016/j.bmcl.2011.04.121] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 04/23/2011] [Accepted: 04/26/2011] [Indexed: 01/15/2023]
Abstract
The synthesis and SAR studies of a novel N-aryl pyridinone class of p38 kinase inhibitors are described. Systematic structural modifications to the HTS lead, 5, led to the identification of (-)-4a as a clinical candidate for the treatment of inflammatory diseases. Additionally, the chiral synthesis and properties of (-)-4a are described.
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Affiliation(s)
- Shaun R Selness
- Department of Medicinal Chemistry, Pfizer Corporation, 700 Chesterfield Parkway West, Chesterfield, MO 63017, United States.
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3
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Selness SR, Devraj RV, Monahan JB, Boehm TL, Walker JK, Devadas B, Durley RC, Kurumbail R, Shieh H, Xing L, Hepperle M, Rucker PV, Jerome KD, Benson AG, Marrufo LD, Madsen HM, Hitchcock J, Owen TJ, Christie L, Promo MA, Hickory BS, Alvira E, Naing W, Blevis-Bal R. Discovery of N-substituted pyridinones as potent and selective inhibitors of p38 kinase. Bioorg Med Chem Lett 2009; 19:5851-6. [DOI: 10.1016/j.bmcl.2009.08.082] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Revised: 08/21/2009] [Accepted: 08/24/2009] [Indexed: 11/28/2022]
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4
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Durley RC, Parnas BL, Weiss RH. Synthesis of high specific activity tritium labeled (E)-6-(bromomethylene)-tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one as a selective probe for calcium-independent phospholipase a2. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580310907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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5
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Reinhard EJ, Wang JL, Durley RC, Fobian YM, Grapperhaus ML, Hickory BS, Massa MA, Norton MB, Promo MA, Tollefson MB, Vernier WF, Connolly DT, Witherbee BJ, Melton MA, Regina KJ, Smith ME, Sikorski JA. Discovery of a simple picomolar inhibitor of cholesteryl ester transfer protein. J Med Chem 2003; 46:2152-68. [PMID: 12747787 DOI: 10.1021/jm020528+] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel series of substituted N-[3-(1,1,2,2-tetrafluoroethoxy)benzyl]-N-(3-phenoxyphenyl)-trifluoro-3-amino-2-propanols is described which potently and reversibly inhibit cholesteryl ester transfer protein (CETP). Starting from the initial lead 1, various substituents were introduced into the 3-phenoxyaniline group to optimize the relative activity for inhibition of the CETP-mediated transfer of [3H]-cholesteryl ester from HDL donor particles to LDL acceptor particles either in buffer or in human serum. The better inhibitors in the buffer assay clustered among compounds in which the phenoxy group was substituted at the 3, 4, or 5 positions. In general, small lipophilic alkyl, haloalkyl, haloalkoxy, and halogen moieties increased potency relative to 1, while analogues containing electron-donating or hydrogen bond accepting groups exhibited lower potency. Compounds with polar or strong electron-withdrawing groups also displayed lower potency. Replacement of the phenoxy ring in 1 with either simple aliphatic or cycloalkyl ethers as well as basic heteroaryloxy groups led to reduced potency. From the better compounds, a representative series 4a-i was prepared as the chirally pure R(+) enantiomers, and from these, the 4-chloro-3-ethylphenoxy analogue was identified as a potent inhibitor of CETP activity in buffer (4a, IC50 0.77 nM, 59 nM in human serum). The simple R(+) enantiomer 4a represents the most potent acyclic CETP inhibitor reported. The chiral synthesis and biochemical characterization of 4a are reported along with its preliminary pharmacological assessment in animals.
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Affiliation(s)
- Emily J Reinhard
- Pharmacia Discovery Research (Pfizer Global Research and Development), 700 Chesterfield Parkway West, Chesterfield, Missouri 63017-1732, USA
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6
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Durley RC, Grapperhaus ML, Hickory BS, Massa MA, Wang JL, Spangler DP, Mischke DA, Parnas BL, Fobian YM, Rath NP, Honda DD, Zeng M, Connolly DT, Heuvelman DM, Witherbee BJ, Melton MA, Glenn KC, Krul ES, Smith ME, Sikorski JA. Chiral N,N-disubstituted trifluoro-3-amino-2-propanols are potent inhibitors of cholesteryl ester transfer protein. J Med Chem 2002; 45:3891-904. [PMID: 12190312 DOI: 10.1021/jm020038h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel series of substituted N-benzyl-N-phenyl-trifluoro-3-amino-2-propanols are described that reversibly inhibit cholesteryl ester transfer protein (CETP). Starting with screening lead 22, various structural features were explored with respect to inhibition of the CETP-mediated transfer of [(3)H]cholesterol from high-density cholesterol donor particles to low-density cholesterol acceptor particles. The free hydroxyl group of the propanol was required for high potency, since acylation or alkylation reduced activity. High inhibitory potency was also associated with 3-ether moieties in the aniline ring, and the highest potencies were exhibited by 3-phenoxyaniline analogues. Activity was substantially reduced by oxidation or substitution in the methylene of the benzylic group, implying that the benzyl ring orientation was important for activity. In the benzylic group, substitution at the 3-position was preferred over either the 2- or the 4-positions. Highest potencies were observed with inhibitors in which the 3-benzylic substituent had the potential to adopt an out of plane orientation with respect to the phenyl ring. The best 3-benzylic substituents were OCF(2)CF(2)H (42, IC(50) 0.14 microM in buffer, 5.6 microM in human serum), cyclopentyl (39), 3-iso-propoxy (27), SCF(3) (67), and C(CF(3))(2)OH (36). Separation of 42 into its enantiomers unexpectedly showed that the minor R(+) enantiomer 1a was 40-fold more potent (IC(50) 0.02 microM in buffer, 0.6 microM in human serum) than the major S(-) enantiomer 1b, demonstrating that the R-chirality at the propanol 2-position is key to high potency in this series. The R(+) enantiomer 1a represents the first reported acyclic CETP inhibitor with submicromolar potency in plasma. A chiral synthesis of 1a is reported.
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Affiliation(s)
- Richard C Durley
- Pharmacia Discovery Research, 700 Chesterfield Parkway North, St. Louis, Missouri 63198, USA.
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7
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Massa MA, Spangler DP, Durley RC, Hickory BS, Connolly DT, Witherbee BJ, Smith ME, Sikorski JA. Novel heteroaryl replacements of aromatic 3-tetrafluoroethoxy substituents in trifluoro-3-(tertiaryamino)-2-propanols as potent inhibitors of cholesteryl ester transfer protein. Bioorg Med Chem Lett 2001; 11:1625-8. [PMID: 11425523 DOI: 10.1016/s0960-894x(01)00244-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A series of novel N,N-disubstituted trifluoro-3-amino-2-propanols has been prepared as potent inhibitors of cholesteryl ester transfer protein (CETP). Modifying the aromatic 3-tetrafluoroethoxy group in the lead molecule 1a with various heteroaryl moieties produced new 2-furyl analogues 2a,b with submicromolar potency in vitro.
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Affiliation(s)
- M A Massa
- Pharmacia Discovery Research, 700 Chesterfield Parkway North, 63198, St. Louis, MO, USA.
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8
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Affiliation(s)
- F S Mathews
- Dept. of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
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9
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Durley RC, Grapperhaus ML, Massa MA, Mischke DA, Parnas BL, Fobian YM, Rath NP, Honda DD, Zeng M, Connolly DT, Heuvelman DM, Witherbee BJ, Glenn KC, Krul ES, Smith ME, Sikorski JA. Discovery of chiral N,N-disubstituted trifluoro-3-amino-2-propanols as potent inhibitors of cholesteryl ester transfer protein. J Med Chem 2000; 43:4575-8. [PMID: 11101348 DOI: 10.1021/jm000337b] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R C Durley
- Pharmacia Discovery Research, 700 Chesterfield Parkway North, St. Louis, Missouri 63198, USA.
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10
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Connolly DT, Witherbee BJ, Melton MA, Durley RC, Grapperhaus ML, McKinnis BR, Vernier WF, Babler MA, Shieh JJ, Smith ME, Sikorski JA. Stereospecific inhibition of CETP by chiral N,N-disubstituted trifluoro-3-amino-2-propanols. Biochemistry 2000; 39:13870-9. [PMID: 11076528 DOI: 10.1021/bi001356q] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chiral N,N-disubstituted trifluoro-3-amino-2-propanols represent a recently discovered class of compounds that inhibit the neutral lipid transfer activity of cholesteryl ester transfer protein (CETP). These compounds all contain a single chiral center that is essential for inhibitory activity. (R,S)SC-744, which is composed of a mixture of the two enantiomers, inhibits CETP-mediated transfer of [(3)H]cholesteryl ester ([(3)H]CE) from HDL donor particles to LDL acceptor particles with an IC(50) = 200 nM when assayed using a reconstituted system in buffer and with an IC(50) = 6 microM when assayed in plasma. Upon isolation of the enantiomers, it was found that the (R,+) enantiomer, SC-795, was about 10-fold more potent than the mixture, and that the (S,-) enantiomer, SC-794, did not have significant inhibitory activity (IC(50) > 0.8 microM). All of the activity of the (S,-)SC-794 enantiomer could be accounted for by contamination of this sample with a residual 2% of the highly potent (R,+) enantiomer, SC-795. The IC(50) of (R,+)SC-795, 20 nM, approached the concentration of CETP (8 nM) in the buffer assay. These chiral N,N-disubstituted trifluoro-3-amino-2-propanols were found to associate with both LDL and HDL, but did not disrupt overall lipoprotein structure. They did not affect the on or off rates of CETP binding to HDL disk particles. Inhibition was highly specific since the activities of phospholipid transfer protein and lecithin cholesterol acyl transferase were not affected. Competition experiments showed that the more potent enantiomer (R)SC-795 prevented cholesteryl ester binding to CETP, and direct binding experiments demonstrated that this inhibitor bound to CETP with high affinity and specificity. It is estimated, based on the relative concentrations of inhibitor and lipid in the transfer assay, that (R)SC-795 binds approximately 5000-fold more efficiently to CETP than the natural ligand, cholesteryl ester. We conclude that these chiral N,N-disubstituted trifluoro-3-amino-2-propanol compounds do not affect lipoprotein structure or CETP-lipoprotein recognition, but inhibit lipid transfer by binding to CETP reversibly and stereospecifically at a site that competes with neutral lipid binding.
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Affiliation(s)
- D T Connolly
- Pharmacia Discovery Research, 800 North Lindbergh Boulevard, St. Louis, Missouri 63167, USA.
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11
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Mowat CG, Beaudoin I, Durley RC, Barton JD, Pike AD, Chen ZW, Reid GA, Chapman SK, Mathews FS, Lederer F. Kinetic and crystallographic studies on the active site Arg289Lys mutant of flavocytochrome b2 (yeast L-lactate dehydrogenase). Biochemistry 2000; 39:3266-75. [PMID: 10727218 DOI: 10.1021/bi9925975] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Flavocytochrome b(2) from Saccharomyces cerevisiae couples L-lactate dehydrogenation to cytochrome c reduction. The crystal structure of the native yeast enzyme has been determined [Xia, Z.-X., and Mathews, F. S. (1990) J. Mol. Biol. 212, 837-863] as well as that of the sulfite adduct of the recombinant enzyme produced in Escherichia coli [Tegoni, M., and Cambillau, C. (1994) Protein Sci. 3, 303-313]; several key active site residues were identified. In the sulfite adduct crystal structure, Arg289 adopts two alternative conformations. In one of them, its side chain is stacked against that of Arg376, which interacts with the substrate; in the second orientation, the R289 side chain points toward the active site. This residue has now been mutated to lysine and the mutant enzyme, R289K-b(2), characterized kinetically. Under steady-state conditions, kinetic parameters (including the deuterium kinetic isotope effect) indicate the mutation affects k(cat) by a factor of about 10 and k(cat)/K(M) by up to nearly 10(2). Pre-steady-state kinetic analysis of flavin and heme reduction by lactate demonstrates that the latter is entirely limited by flavin reduction. Inhibition studies on R289K-b(2) with a range of compounds show a general rise in K(i) values relative to that of wild-type enzyme, in line with the elevation of the K(M) for L-lactate in R289K-b(2); they also show a change in the pattern of inhibition by pyruvate and oxalate, as well as a loss of the inhibition by excess substrate. Altogether, the kinetic studies indicate that the mutation has altered the first step of the catalytic cycle, namely, flavin reduction; they suggest that R289 plays a role both in Michaelis complex and transition-state stabilization, as well as in ligand binding to the active site when the flavin is in the semiquinone state. In addition, it appears that the mutation has not affected electron transfer from fully reduced flavin to heme, but may have slowed the second intramolecular ET step, namely, transfer from flavin semiquinone to heme b(2). Finally, the X-ray crystal structure of R289K-b(2), with sulfite bound at the active site, has been determined to 2.75 A resolution. The lysine side chain at position 289 is well-defined and in an orientation that corresponds approximately to one of the alternative conformations observed in the structure of the recombinant enzyme-sulfite complex [Tegoni, M., and Cambillau, C. (1994) Protein Sci. 3, 303-313]. Comparisons between the R289K-b(2) and wild-type structures allow the kinetic results to be interpreted in a structural context.
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Affiliation(s)
- C G Mowat
- Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, U.K
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12
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Penning TD, Chandrakumar NS, Chen BB, Chen HY, Desai BN, Djuric SW, Docter SH, Gasiecki AF, Haack RA, Miyashiro JM, Russell MA, Yu SS, Corley DG, Durley RC, Kilpatrick BF, Parnas BL, Askonas LJ, Gierse JK, Harding EI, Highkin MK, Kachur JF, Kim SH, Krivi GG, Villani-Price D, Pyla EY, Smith WG. Structure-activity relationship studies on 1-[2-(4-Phenylphenoxy)ethyl]pyrrolidine (SC-22716), a potent inhibitor of leukotriene A(4) (LTA(4)) hydrolase. J Med Chem 2000; 43:721-35. [PMID: 10691697 DOI: 10.1021/jm990496z] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Leukotriene B(4) (LTB(4)) is a pro-inflammatory mediator that has been implicated in the pathogenesis of a number of diseases including inflammatory bowel disease (IBD) and psoriasis. Since the action of LTA(4) hydrolase is the rate-limiting step for LTB(4) production, this enzyme represents an attractive pharmacological target for the suppression of LTB(4) production. From an in-house screening program, SC-22716 (1, 1-[2-(4-phenylphenoxy)ethyl]pyrrolidine) was identified as a potent inhibitor of LTA(4) hydrolase. Structure-activity relationship (SAR) studies around this structural class resulted in the identification of a number of novel, potent inhibitors of LTA(4) hydrolase, several of which demonstrated good oral activity in a mouse ex vivo whole blood assay.
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Affiliation(s)
- T D Penning
- Departments of Medicinal Chemistry, Structure-Activity Screening Program, Inflammatory Diseases Research, and Molecular Pharmacology, Searle Research and Development, Monsanto Company, Skokie, Illinois 60077, USA.
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13
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Affiliation(s)
- L M Cunane
- Department of Biochemistry and Molecular Biophysics, Washington University Medical School, St. Louis, MO 63110, USA
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14
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Zhu Z, Cunane LM, Chen Z, Durley RC, Mathews FS, Davidson VL. Molecular basis for interprotein complex-dependent effects on the redox properties of amicyanin. Biochemistry 1998; 37:17128-36. [PMID: 9860825 DOI: 10.1021/bi9817919] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The quinoprotein methylamine dehydrogenase (MADH), type I copper protein amicyanin, and cytochrome c-551i form a complex within which interprotein electron transfer occurs. It was known that complex formation significantly lowered the oxidation-reduction midpoint potential (Em) value of amicyanin, which facilitated an otherwise thermodynamically unfavorable electron transfer to cytochrome c-551i. Structural, mutagenesis, and potentiometric studies have elucidated the basis for this complex-dependent change in redox properties. Positively charged amino acid residues on the surface of amicyanin are known to stabilize complex formation with MADH and influence the ionic strength dependence of complex formation via electrostatic interactions. Altering the charges of these residues by site-directed mutagenesis had no effect on the Em value of amicyanin, ruling out charge neutralization as the basis for the complex-dependent changes in redox properties. The Em value of free amicyanin varies with pH and exhibits a pKa value for the reduced form of 7.5. The crystal structure of reduced amicyanin at pH 4.4 reveals that His95, which serves as a ligand for Cu2+, has rotated by 180 degrees about the Cbeta-Cgamma bond relative to its position in oxidized amicyanin and is no longer in the copper coordination sphere. At pH 7.7, the crystal structure of reduced amicyanin contains an approximately equal distribution of two active-site conformers. One is very similar to the structure of reduced amicyanin at pH 4.4, and the other is very similar to the structure of oxidized amicyanin at pH 4.8. Potentiometric analysis of amicyanin in complex with MADH indicates that its Em value is not pH-dependent from pH 6.5 to 8.5, and exhibits an Em value similar to that of free amicyanin at high pH. The structure of reduced amicyanin at pH 4.4, with His95 protonated and "flipped", was modeled into the structure of the complex of oxidized amicyanin with MADH. This showed that in the complex, the redox-linked pH-dependent rotation of His95 is hindered because it would cause an overlap of van der Waals' radii with residues of MADH. These results demonstrate that protein-protein interactions profoundly affect the redox properties of this type I copper protein by restricting a pH-dependent, redox-linked conformational change of one of the copper ligands.
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Affiliation(s)
- Z Zhu
- Department of Biochemistry, The University of Mississippi Medical Center, Jackson 39216-4505, USA
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15
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Wang D, Girard TJ, Kasten TP, LaChance RM, Miller-Wideman MA, Durley RC. Inhibitory activity of unsaturated fatty acids and anacardic acids toward soluble tissue factor-factor VIIa complex. J Nat Prod 1998; 61:1352-1355. [PMID: 9834151 DOI: 10.1021/np980117p] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Five compounds, which inhibited the amidolytic activity of soluble tissue factor/activated factor VII complex (sTF/VIIa), were isolated from two traditional Chinese medicinal plants commonly used in the treatment of cardiovascular and cerebrovascular diseases. The active compounds were found to be linolenic, linoleic, and oleic acids from roots of Salvia miltiorrhiza; and two anacardic acids, 6-(8'Z-pentadecenyl)- and 6-(10'Z-heptadecenyl)-salicylic acids, from leaves of Ginkgo biloba. The IC50 values were in the range 30-80 micromol/L. Palmitic acid, isolated from roots of Salvia miltiorrhiza, and 2-[(3',7',11',15'-tetramethyl)-2'E,6'E,10'E, 14'E-hexadecatetraenyl]-1,4-hydroquinone, isolated from the marine sponge Adocia viola, did not inhibit sTF/VIIa. Further expansion of the structure-activity relationship to include anacardic acids, 6-(8'Z,11'Z-heptadecadienyl)- and 6-(8'Z, 11'Z, 14'Z-heptadecatrienyl)-salicylic acids from leaves of Anacardium spondias, and other fatty acids demonstrated that at least one cis double bond was essential for inhibitory activity, and that fatty acids containing two or three cis double bonds were optimal. Evidence from preincubation studies implied that these fatty acids may exert their effect by binding to VIIa and consequently preventing binding of sTF to VIIa.
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Affiliation(s)
- D Wang
- Searle Discovery Research, Monsanto Company, 700 Chesterfield Parkway North, St. Louis, Missouri 63198, USA
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16
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Chen L, Doi M, Durley RC, Chistoserdov AY, Lidstrom ME, Davidson VL, Mathews FS. Refined crystal structure of methylamine dehydrogenase from Paracoccus denitrificans at 1.75 A resolution. J Mol Biol 1998; 276:131-49. [PMID: 9514722 DOI: 10.1006/jmbi.1997.1511] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The three-dimensional structure of the quinoprotein methylamine dehydrogenase from Paracoccus denitrificans has been refined at 1.75 A resolution utilizing the DNA-based protein sequence. The final model incorporates 8034 atoms per molecule, including 552 molecules of solvent, and gives an R-factor of 0.163. The molecule is an H2L2 hetero-tetramer containing a non-crystallographic 2-fold axis of symmetry. The 373-residue H subunit is folded into seven repeats of a four-stranded antiparallel beta-sheet motif, arranged in a propeller-like pattern about a pseudo-7-fold rotational axis of symmetry. Each L subunit contains 131 residues folded in a tight structure composed of five beta-strands in two sheets and crosslinked by six disulfide bonds. In addition there is an intrasubunit covalent linkage between two tryptophan side-chains that form the unique redox center, tryptophan tryptophylquinone (TTQ). The active site contains the O-6 carbonyl of TTQ, the side-chains of Asp32L Asp76L, Tyr119L and Thr122L, and two solvent molecules. A potential "gate" (Phe55H) separates the closed active-site cavity from a channel containing a group of highly ordered water molecules to bulk solvent. Phe55H and Tyr119L, and a number of neighboring oxygen atoms, may also provide a binding site for monovalent cations that are known to affect the reactivity and spectral properties of TTQ as well as the oxidative half reaction. The overall reaction has been dissected into a number of discrete steps that may require participation by several individual amino acid residues in the active site acting as general acids and bases.
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Affiliation(s)
- L Chen
- Department of Biochemistry and Molecular Biophysics, Washington University Medical School, St. Louis, MO 63110, USA
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17
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Hunter MS, Corley DG, Carron CP, Rowold E, Kilpatrick BF, Durley RC. Four new clerodane diterpenes from the leaves of Casearia guianensis which inhibit the interaction of leukocyte function antigen 1 with intercellular adhesion molecule 1. J Nat Prod 1997; 60:894-899. [PMID: 9322361 DOI: 10.1021/np970141n] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Four new clerodane diterpenes, casearinols A and B (1 and 2) and casearinones A and B (3 and 4), were isolated from the leaves of Casearia guianensis. These immunomodulatory compounds have been structurally elucidated primarily on the basis of 2D NMR analysis and spectral data comparison with known compounds. These compounds inhibited the binding of T-cell leukocyte function antigen 1 to intercellular adhesion molecule 1.
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Affiliation(s)
- M S Hunter
- Searle Research and Development, Monsanto Company, St. Louis, Missouri 63198, USA
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18
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Parnas BL, Durley RC, Rhoden EE, Kilpatrick BF, Makkar N, Thomas KE, Smith WG, Corley DG. Isolation and structure of leukotriene-A4 hydrolase inhibitor: 8(S)-amino-2(R)-methyl-7-oxononanoic acid produced by Streptomyces diastaticus. J Nat Prod 1996; 59:962-964. [PMID: 8904845 DOI: 10.1021/np9603986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The novel amino acid 8(S)-amino-2(R)-methyl-7-oxononanoic acid (1) was isolated from the soil-borne microorganism Streptomyces diastaticus during our screening for inhibitors of leukotriene-A4 hydrolase (LTA4H), a requisite enzyme in the biosynthesis of the potent inflammatory mediator leukotriene-B4 (LTB4). The structure of 1 was determined by detailed spectroscopic analyses and is related to 7-keto-8-aminopelargonic acid (2), a biosynthetic precursor of biotin. The relative potency of 1 (LTA4H IC50 = 0.6 microM) warranted further biological studies.
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Affiliation(s)
- B L Parnas
- Searle Research and Development, Monsanto Company, St. Louis, Missouri 63198, USA
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19
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Cunane LM, Chen ZW, Durley RC, Mathews FS. X-ray Structure of the Cupredoxin Amicyanin, fromParacoccus denitrificans, Refined at 1.31 Å Resolution. Acta Crystallogr D Biol Crystallogr 1996; 52:676-86. [PMID: 15299631 DOI: 10.1107/s0907444996001072] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
High-resolution X-ray diffraction data to d(min) = 1.31 A were collected on a Xuong-Hamlin area detector from crystals of the blue-copper protein amicyanin, isolated from P. denitrificans. With coordinates from the earlier 2.0 A structure determination as a starting point, simulated annealing and restrained positional and temperature factor refinements using the program X-PLOR resulted in a final R factor of 15.5%, based on 21 131 unique reflections in the range 8.0-1.3 A. Comparison of the 1.31 A structure with that at 2.0 A shows the same basic features. However, the high-resolution electron-density maps clearly reveal additional solvent molecules and significant discrete disorder in protein side chains and within the solvent structure. As a consequence of modelling side-chain disorder, several new hydrogen-bonding interactions were identified.
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Affiliation(s)
- L M Cunane
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
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20
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Merli A, Brodersen DE, Morini B, Chen Z, Durley RC, Mathews FS, Davidson VL, Rossi GL. Enzymatic and electron transfer activities in crystalline protein complexes. J Biol Chem 1996; 271:9177-80. [PMID: 8621571 DOI: 10.1074/jbc.271.16.9177] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Enzymatic and electron transfer activities have been studied by polarized absorption spectroscopy in single crystals of both binary and ternary complexes of methylamine dehydrogenase (MADH) with its redox partners. Within the crystals, MADH oxidizes methylamine, and the electrons are passed from the reduced tryptophan tryptophylquinone (TTQ) cofactor to the copper of amicyanin and to the heme of cytochrome c551i via amicyanin. The equilibrium distribution of electrons among the cofactors, and the rate of heme reduction after reaction with substrate, are both dependent on pH. The presence of copper in the ternary complex is not absolutely required for electron transfer from TTQ to heme, but its presence greatly enhances the rate of electron flow to the heme.
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Affiliation(s)
- A Merli
- Istituto di Scienze Biochimiche, Universita di Parma, Parma, Italy
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21
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Durley RC, Mathews FS. Refinement and structural analysis of bovine cytochrome b5 at 1.5 Å Resolution. Acta Crystallogr D Biol Crystallogr 1996; 52:65-76. [PMID: 15299727 DOI: 10.1107/s0907444995007827] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The structure of bovine liver cytochrome b(5), a soluble 93-residue proteolytic fragment of a 16 kDa membrane-bound hemoprotein, initially solved at 2.0 A resolution, has been refined at 1.5 A using data collected on a diffractometer. Refinement to 2.0 A resolution used the Hendrickson-Konnert procedure PROLSQ and was then extended to 1.5 A resolution using the program PROFFT. Only residues 3-87 could be identified in the model and these residues together with 93 water molecules gave an agreement factor of R = 0.161 for data in the resolution range 1.5-5 A. The structure was finally refined using the program X-PLOR, which enabled alternate conformers to be modelled for several surface side chains. Residues 1 and 2 at the amino terminus of the protein and residue 88 near the carboxyl terminus could be identified from these electron-density maps. However the remaining disordered carboxy-terminal residues could not successfully be included in the model. A total of 117 solvent molecules were included in the final refinement to give R = 0.164 for the data between 1.5 and 10 A.
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Affiliation(s)
- R C Durley
- Department of Biochemistry and Molecular Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
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22
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Abstract
The crystal structure of a ternary protein complex has been determined at 2.4 angstrom resolution. The complex is composed of three electron transfer proteins from Paracoccus denitrificans, the quinoprotein methylamine dehydrogenase, the blue copper protein amicyanin, and the cytochrome c551i. The central region of the c551i is folded similarly to several small bacterial c-type cytochromes; there is a 45-residue extension at the amino terminus and a 25-residue extension at the carboxyl terminus. The methylamine dehydrogenase-amicyanin interface is largely hydrophobic, whereas the amicyanin-cytochrome interface is more polar, with several charged groups present on each surface. Analysis of the simplest electron transfer pathways between the redox partners points out the importance of other factors such as energetics in determining the electron transfer rates.
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Affiliation(s)
- L Chen
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110
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23
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Corley DG, Miller-Wideman M, Durley RC. Isolation and structure of harzianum A: a new trichothecene from Trichoderma harzianum. J Nat Prod 1994; 57:422-425. [PMID: 8201317 DOI: 10.1021/np50105a019] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A new trichothecene, harzianum A [1], was isolated from the soil-borne fungus Trichoderma harzianum. The structure of 1 was determined by extensive spectral analyses including the nmr techniques of PS-COSY, HMQC, HMBC, and NOESY. Harzianum A [1] contains a (Z,E,E)-2,4,6-octatriendioic acid esterified on the 4 beta hydroxyl group of trichodermol and is structurally related to the trichoverroids. Harzianum A [1] showed no cytotoxicity against baby hamster kidney cells, no activity against Gram-negative and Gram-positive bacteria, but modest antifungal activity at 100 micrograms/ml.
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Affiliation(s)
- D G Corley
- Monsanto Company, St. Louis, Missouri 63198
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24
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Abstract
The objective of these experiments was to determine the origin of 2-hydroxy-4-(methylthio)-butanoic acid (HMB) detected in the liver and excreta of chicks that had never been fed Alimet (an 88% aqueous solution of HMB) or MHA (an 86% calcium salt of HMB). Gas chromatography and mass spectrometry were used to identify HMB in these birds. A normal biochemical pathway of 5'-deoxy-5'-methylthioadenosine (MTA) is proposed as the source of naturally occurring HMB. Studies of conversion of [methyl-14C]MTA to L-methionine by chick liver enzymesØe showed that radiolabeled HMB and 2-oxo-4-(methylthio)butanoic acid (keto-methionine) were synthesized during the reaction. Specific radioactivities of labeled HMB and keto-methionine showed that HMB is not synthesized from keto-methionine. Fractionation studies indicated that radiolabeled HMB formed from [14C]MTA could be used in the synthesis of L-methionine in the presence of peroxisomes and/or mitochondrial enzymes. In this way, HMB synthesized from MTA by chick liver enzymes functions as a precursor of L-methionine and as an intermediate in a naturally occurring pathway for the synthesis of L-methionine in the chick.
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Affiliation(s)
- J J Dibner
- Monsanto Company, Animals Sciences Division, Chesterfield, MO 63198
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25
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Durley RC, Sharp CR, Maki SL, Brenner ML, Carnes MG. Immunoaffinity techniques applied to the purification of gibberellins from plant extracts. Plant Physiol 1989; 90:445-51. [PMID: 16666791 PMCID: PMC1061744 DOI: 10.1104/pp.90.2.445] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The use of immunoaffinity columns containing anti-gibberellin (GA) antibodies for the selective purification of GAs in plant extracts is described. GA(1), GA(3), GA(4), GA(5), GA(7), and GA(9) conjugates to bovine serum albumin were synthesized and used to elicit anti-GA polyclonal antibodies (Abs) in rabbits. Protein A purified rabbit serum, containing a mixture of anti-GA Abs, was immobilized on matrices of Affi-gel 10 or Fast-Flow Sepharose 4B. Columns of these immunosorbents retained a wide range of C-19 GA methyl esters, but no C-20 GA methyl esters. Quantitative recovery of C-19 GA methyl esters was achieved from the columns, which, after reequilibration in buffer, could be reused up to 500 times. The immunosorbents were tested by examination of extracts from immature soybean and pea seeds. GAs were initially purified by passing the extracts through DEAE-cellulose and concentrating them on octadecylsilica. The extracts were methylated and further purified on the mixed anti-GA immunoaffinity columns. GAs were detected and quantified as methyl esters or methyl ester trimethylsilyl ethers by gas chromatography-mass spectrometry-selected ion monitoring. GA(7) was found in soybean seeds, 17 days after anthesis, at low levels (8.8 nanograms per gram fresh weight). C-19 GAs were examined in cotyledons, embryonic axes, and testae of G2 pea seeds harvested 20 days after anthesis. High levels of GA(20) and GA(29) were found in cotyledons (3580 and 310 nanograms per gram fresh weight, respectively) and embryonic axes (5375 and 1430 nanograms per gram) fresh weight, respectively). Lower levels of GA(9) were found in cotyledons and embryonic axes (147 and 161 nanograms per gram fresh weight, respectively). GA(9) was the major GA of testae at levels of 195 nanograms per gram fresh weight. Trace quantities of GA(20) and GA(51) were also observed in testae.
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Affiliation(s)
- R C Durley
- Monsanto Company, Saint Louis, Missouri 63198
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26
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Krieter PA, Olins GM, Verrett SP, Durley RC. In vivo metabolism of atrial natriuretic peptide: identification of plasma metabolites and enzymes responsible for their generation. J Pharmacol Exp Ther 1989; 249:411-7. [PMID: 2524586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The in vivo metabolism of atrial natriuretic peptide (ANP) has been studied in the rat after i.v. administration of either [106Phe-14C]- or [126Tyr-125I]-ANP(103-126). Plasma samples containing radioactive peptides were separated by reverse-phase high-performance liquid chromatography. The major plasma metabolites were [125I]Tyr and [14C]Phe for the iodinated and 14C-labeled peptides, respectively. Both peptides had ANP(104/5-126) as a metabolite. Administration of labeled peptide by either bolus or infusion produced the same metabolite profile. To determine which enzymes were responsible for generating these initial metabolites, animals were first dosed with various protease inhibitors before the infusion of [14C]ANP(103-126). The amino-peptidase inhibitor bestatin and the angiotensin converting enzyme inhibitor captopril caused 54 and 66% increases in plasma ANP(103-126), respectively, but no other effects. Administration of the endopeptidase 24.11 inhibitor thiorphan led to a 158% increase of ANP(103-126) in plasma and an 11-fold increase in ANP(104/5-126). The latter metabolite could be selectively decreased by pretreatment with bestatin in combination with thiorphan. The results demonstrate that the initial plasma metabolites of ANP(103-126) are due to the activity of endopeptidase 24.11, a bestatin-sensitive aminopeptidase, and a carboxypeptidase. The plasma clearance of the peptide is probably also due to cellular binding and uptake in combination with glomerular filtration as very few plasma metabolites were observed even at very high rates of ANP(103-126) infusion.
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27
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Carlson DR, Dyer DJ, Cotterman CD, Durley RC. The Physiological Basis for Cytokinin Induced Increases in Pod Set in IX93-100 Soybeans. Plant Physiol 1987; 84:233-9. [PMID: 16665422 PMCID: PMC1056562 DOI: 10.1104/pp.84.2.233] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Previous investigations have shown the feasibility of increasing pod number on legumes by the application of 6-benzylaminopurine (BA) directly to the raceme. These investigations were designed to determine what reproductive parameter was affected by cytokinin application, and if these applications were overcoming a deficiency in root-produced cytokinins during late flowering. Five individual main stem racemes on greenhouse grown soybeans (Glycine max L. Merr.) were treated with 2 millimolar BA. A single application of BA when pods appeared at 25 to 50% of the proximal floral positions resulted in a 58% increase in pod set due primarily to a 33% reduction in floral abscission. Applications of BA at later intervals also resulted in significant reductions in total abscission. When three applications of BA were imposed on the upper five nodes of field grown soybeans, total pod number and seed weight were significantly increased in this section of the canopy by 27 and 18%, respectively. Throughout the flowering period, root pressure exudate was sampled for the subsequent separation and quantification of zeatin, dihydrozeatin, zeatin riboside, dihydrozeatin riboside, and isopentenyladenine. Total cytokinin flux peaked from 0 to 9 days after flowering began, and then dropped to one-half of this level by 15 days postanthesis. The probability that a flower would initiate a pod was directly related to the concentration of total cytokinins present in the exudate when the flower opened.
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Affiliation(s)
- D R Carlson
- Monsanto Agricultural Company, St. Louis, Missouri 63198
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28
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Abstract
Tritium-labeled gibberellin A(20) ([(3)H]GA(20)) was applied via the pedicel to immature pods and seeds of dwarf peas and three harvests were made at days 5, 10, and 23 (mature) after application. Of the five metabolites of [(3)H]GA(20), the three in highest yield were GA(29), an alpha,beta-unsaturated ketone, and a compound (B), whose structure was only tentatively assigned. The metabolic sequence GA(20) --> GA(29) --> compound B --> the ketone was indicated. The amount of [(3)H]GA(29) in both seeds and pods was highest at day 5 and declined to its lowest level at maturity. The amount of the [(3)H]ketone in the seed increased with time to its highest level at maturity. It is suggested that compound B and the ketone represent the major pathway of catabolism of GA(29), a 2beta-hydroxylated GA of low biological activity, and that the ketone is not metabolized, or only slowly metabolized, during seed maturation.
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Affiliation(s)
- R C Durley
- Department of Biology, University of Calgary, Calgary, Alberta T2N 1N4 Canada
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29
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Durley RC, Kannangara T, Simpson GM. Analysis of abscisins and 3-indolylacetic acid in leaves of Sorghum bicolor by high performance liquid chromatography. ACTA ACUST UNITED AC 1978. [DOI: 10.1139/b78-019] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The growth regulators abscisic acid (ABA), phaseic acid, dihydrophaseic acid, and 3-indolylacetic acid (IAA) have been detected and the levels were measured in extracts of leaves from Sorghum bicolor using high performance liquid chromatography (HPLC). For purification of extracts, columns contained 37- to 75-μm-diameter octadecylsilica. For analysis of the growth regulators, microoctadecylsilica columns were used. Both columns were used in the reverse phase mode. The efficiency and resolution of the microcolumn combined with the high sensitivity of the ultraviolet absorption microcell detector could accurately determine as little as 2 ng of ABA and 6 ng of IAA. The method is suitable for routine analysis of levels of regulators in moderately large numbers of plant extracts.
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30
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McInnes AG, Smith DG, Durley RC, Pharis RP, Arsenault GP, MacMillan J, Gaskin P, Vining LC. Biosynthesis of gibberellins in Gibberella fujikuroi. Gibberellin A47. Can J Biochem 1977; 55:728-35. [PMID: 560901 DOI: 10.1139/o77-105] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Two minor radioactive products in cultures of G. fujikuroi strain ACC917 supplemented with labeled gibberellin A4 have been identified as the 2alpha-hydroxy derivative, gibberellin A47, and the hydrate, gibberellin A2. In addition, evidence was obtained by combined gas chromatography--mass spectrometry for the formation of 3-O-acetylgibberellin A1,3-O-acetylgibberellin A3, and gibberellin A20 by the culture. The time course of gibberellin synthesis in defined and complex media, as well as changes in the relative amounts of radioactive gibberellins formed when [4C]gibberellin A4 was added to cultures at different ages, suggest that the composition of the gibberellin mixture produced is determined by the balance between synthesis and decay of key enzymes in the branching pathway.
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31
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Lance B, Durley RC, Reid DM, Thorpe TA, Pharis RP. Metabolism of [H]Gibberellin A(20) in Light- and Dark-grown Tobacco Callus Cultures. Plant Physiol 1976; 58:387-92. [PMID: 16659684 PMCID: PMC542252 DOI: 10.1104/pp.58.3.387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The growth of tobacco callus in culture (previously shown to contain gibberellin [GA]-like substances), and its ability to metabolize [(3)H]-GA(20) were examined. Growth rates, in the presence and absence of exogenously applied GA, were examined in light and dark conditions. Dark-grown callus grew at a much faster rate than light-grown and [(3)H]GA(20) was metabolized much more rapidly in darkness than in light.[(3)H]GA(1) was identified by combined gas-liquid chromatography/mass spectrometry as a major product of [(3)H]GA(20), and was found to be a more potent promoter of tobacco callus growth than GA(20).
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Affiliation(s)
- B Lance
- Department of Biology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
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32
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Kamienska A, Durley RC, Pharis RP. Endogenous Gibberellins of Pine Pollen: III. Conversion of 1,2-[H]GA(4) to Gibberellins A(1) and A(34) in Germinating Pollen of Pinus attenuata Lemm. Plant Physiol 1976; 58:68-70. [PMID: 16659622 PMCID: PMC542181 DOI: 10.1104/pp.58.1.68] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Gibberellins A(1) and A(34) (possibly A(2)) were found as products of metabolism of 1,2-[(3)H]GA(4) during germination of Pinus attenuata pollen. The conversion from GA(4) to GA(1) and GA(34) occurred as hydroxylations at atoms C-13 and C-2 of the ent-gibberellane skeleton, respectively. Percentage interconversion of the GA(4) absorbed was in the range of 0.15 to 0.43% for GA(1) and 1.54 to 3.22% for GA(34). Identifications were made on a gas-liquid chromatograph with radioactive monitoring by comparison with standards.
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Affiliation(s)
- A Kamienska
- Department of Biology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
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33
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Durley RC, Bewley JD, Railton ID, Pharis RP. Effects of Light, Abscisic Acid, and N-Benzyladenine on the Metabolism of [H]Gibberellin A(4) in Seeds and Seedlings of Lettuce, cv. Grand Rapids. Plant Physiol 1976; 57:699-703. [PMID: 16659554 PMCID: PMC542102 DOI: 10.1104/pp.57.5.699] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Gibberellin A(4) (GA(4)) can substitute for light in the germination of Grand Rapids lettuce seeds. Seeds imbibed in [(3)H]GA(4) do not convert this to other GAs prior to, or immediately following, visible germination: thus GA(4) alone can promote radicle expansion. Abscisic acid inhibited [(3)H]GA(4)-induced germination, but did not significantly affect [(3)H]GA(4) uptake or metabolism during germination. (6)N-benzyladenine overcame the inhibitory effect of abscisic acid and increased [(3)H]GA(4) uptake, although radicle emergence was delayed somewhat.During hypocotyl extension there was a large conversion of [(3)H]GA(4) to [(3)H]GA(1) in light or darkness, the major conversion site being the growing root. Hypocotyls of dark-grown seedlings contained more [(3)H]GA(1) than those of light-grown seedlings. The apparent inability of exogenous GA(1) to promote greater hypocotyl extension than GA(4) is related to its poorer uptake. Abacisic acid markedly inhibited hypocotyl expansion, root growth, and the conversion of [(3)H]GA(4) to [(3)H]GA(1).
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Affiliation(s)
- R C Durley
- Department of Biology, University of Calgary, Calgary, Alberta T2N IN4, Canada
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34
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Hoad GV, Pharis RP, Railton ID, Durley RC. Activity of the aldehyde and alcohol of gibberellins A12 and A 14, two derivatives of gibberellin A 15 and four decomposition products of gibberellin A 3 in 13 plant bioassays. Planta 1976; 130:113-120. [PMID: 24424586 DOI: 10.1007/bf00384407] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/1975] [Accepted: 12/27/1975] [Indexed: 06/03/2023]
Abstract
The biological activities of the aldehyde and alcohol of gibberellins (GAs) A12 and A14, 3α-OH-GA15, 3β-OH-GA15 wrong lactone (i.e. GA37 wrong lactone) and the four major decomposition products of GA3 (isogibberellic, allogibberic, epiallogibberic and Δ9(11)-dehydroallogibberic acids) were tested over a wide range of concentrations on 13 plant bioassays in order to ascertain certain of the structural requirements for biological activity. Generally modification of the basic GA-molecule decreased its activity in all assays except for derivatives of GA12 and GA14 (suggesting conversion of these derivatives to more polar, active GAs). Modification of the 3-OH from the usual 3β to 3α configuration markedly reduced activity. Neither the presence of an inverted lactone ring (i.e. 3β-OH-GA15 wrong lactone) nor changes to the lactone ring of GA3 (4→10) to form iso-GA3 (4→2) appreciably reduce activity. Further decomposition of GA3 to allogibberic and Δ9(11)-dehydroallogibberic acid reduced activity only slightly, but epimerization of allogibberic acid at C-9 essentially eliminated biological activity.
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Affiliation(s)
- G V Hoad
- Long Ashton Research Station, University of Bristol, BS18 9AF, Bristol, UK
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35
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Durley RC, Pharis RP, Zeevaart JA. Metabolism of [(3)H]Gibberellin A 20 by plants of Bryophyllum daigremontianum under long- and short-day conditions. Planta 1975; 126:139-149. [PMID: 24430156 DOI: 10.1007/bf00380617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/1975] [Accepted: 07/02/1975] [Indexed: 06/03/2023]
Abstract
[(3)H]Gibberellin A20 ([(3)H]GA20), a native gibberellin of this plant, was injected into mature leaves of Bryophyllum daigremontianum (Hamet et Perr.) Berg. under long- and short-day conditions. It was converted, in order of decreasing yields, to GA29, 3-epi-GA1 (pseudo GA1), C/D-ring-rearranged GA20, and two minor, unidentified metabolites. Identifications were made by gas-liquid chromatography with radioactive monitoring using three different phases. Metabolism to 3-epi-GA1 was greater under short days, particularly in the treated leaf pair, although the absolute amount of GA29 was greater than that of 3-epi-GA1 under both photoperiods. The levels of radioactive metabolites in the shoots above the treated leaf pair gradually increased over a 51-day period, GA29 reaching 5 times the contten of 3-epi-GA1.
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Affiliation(s)
- R C Durley
- Department of Biology, University of Calgary, T2N 1N4, Calgary, Alberta, Canada
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36
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Durley RC, MacMillan J, Simpson TJ, Glen AT, Turner WB. Fungal products. Part XIII. Xanthomegnin, viomellin, rubrosulphin, and viopurpurin, pigments from Aspergillus sulphureus and Aspergillus melleus. ACTA ACUST UNITED AC 1975. [DOI: 10.1039/p19750000163] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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37
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Railton ID, Durley RC, Pharis RP. Metabolism of Tritiated Gibberellin A(9) by Shoots of Dark-grown Dwarf Pea, cv. Meteor. Plant Physiol 1974; 54:6-12. [PMID: 16658838 PMCID: PMC541492 DOI: 10.1104/pp.54.1.6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Tritium-labeled gibberellin A(9) ((3)H-GA(9)) was metabolized by etiolated shoots of dwarf pea (Pisum sativum cv. Meteor) to GA(20), GA(10), 2,3-dihydro-GA(31), and a number of highly polar, acidic GA-like substances. Identifications were made by gasliquid radiochromatography and combined gas chromatography-mass spectrometry. Kinetic studies showed that GA(30) and 2,3-dihydro-GA(31) were produced within 5 hours following (3)H-GA(9) application to pea shoots. The polar GA-like substances were produced between 5 and 10 hours after (3)H-GA(9) application. Levels of GA(10) increased with time, and since no GA(10) was produced during the purification procedures, GA(10) was, in all probability, produced from (3)H-GA(9) within the plant tissue. The radioactive interconversion products produced by pea from (3)H-GA(9) have chromatographic properties similar to biologically active GA-like substances present in etiolated shoots of dwarf pea. Large scale applications of (3)H-GA(9) with very low specific activity to etiolated pea shoots showed that the radioactivity of the interconversion products was correlated exactly with biological activity as assayed by dwarf rice (Oryza sativa cv. Tan-ginbozu).
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Affiliation(s)
- I D Railton
- Department of Biology, University of Calgary, Calgary T2N 1N4, Alberta, Canada
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Durley RC, Pharis RP. Interconversion of gibberellin A4 to gibberellins A 1 and A 34 by dwarf rice, cultivar Tan-ginbozu. Planta 1973; 109:357-361. [PMID: 24474212 DOI: 10.1007/bf00387104] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/1972] [Indexed: 06/03/2023]
Abstract
Interconversion of GA4 to GA1 and GA34 occurred within 24 h of application of 1,2-[(3)H]-GA4 to seedlings of dwarf rice, cv. Tan-ginbozu. Identification was made by direct comparison of the trimethylsilyl ether derivatives of the methyl esters of Silica-gel partition-column fractions on gas-liquid radiochromatography with derivatized GA1 and GA34 standards on three columns: 2% QF-1, 2% SE-30, and 1% XE-60. GA2, an artifact of the purification and chromatography system, may also be formed by the plant. The conversions from GA4 to GA1 and GA34 are single hydroxylations. At least two unidentified radioactive products were also formed by the plant. Interconversions were in the order of 0.3 to 0.8% of applied [(3)H]-GA4.
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Affiliation(s)
- R C Durley
- Department of Biology, University of Calgary, T2N 1N4, Calgary, Alberta, Canada
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Reid DM, Tuing MS, Durley RC, Railton ID. Red-light-enhanced conversion of tritiated gibberellin A9 into other gibberellin-like substances in homogenates of etiolated barley leaves. Planta 1972; 108:67-75. [PMID: 24473746 DOI: 10.1007/bf00386507] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/1972] [Indexed: 06/03/2023]
Abstract
Irradiation of homogenates of etiolated barley leaves with red light resulted in an increase in the levels of gibberellin (GA)-like substances as compared to dark controls. When homogenates were fed with [(3)H]-GA9 there was as incorporation of the radioactivity into a number of other GA's: this process occurred to a greater extent in red light than in darkness, and could be inhibited by boiling the extract prior to addition of the [(3)H]-GA9.
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Affiliation(s)
- D M Reid
- Biology Department, University of Calgary, Calgary, Alberta, Canada
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