Abstract：
:The mechanism by which phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) catalyzes the reversible elimination of ammonia from phenylalanine yielding (E)-cinnamic acid has gained much attention in the recent years. Dehydroalanine is essential for the catalysis. It was assumed that this prostetic group acts as the electrophile, leading to a covalently bonded enzyme-intermediate complex with quarternary nitrogen of phenylalanine. Recently, an alternative mechanism has been suggested in which the enzyme-intermediate complex is formed in a Friedel-Crafts reaction between dehydroalanine and orthocarbon of the aromatic ring. Using semiempirical calculations we have shown that these two alternative mechanisms can be distinguished on the basis of the hydrogen secondary kinetic isotope effect when tritium label is placed in the orthopositions. Our calculations indicated also that the kinetic isotope effect measured using ring-labeled d(5)-phenylalanine could not be used to differentiate these alternative mechanisms. Measured secondary tritium kinetic isotope effect shows strong dependence on the reaction progress, starting at the inverse value of k(H)/k(T) = 0.85 for 5% conversion and reaching the normal value of about 1.15 as the conversion increases to 20%. This dependence has been interpreted in terms of a complex mechanism with initial formation of the Friedel-Crafts type intermediate.
journal_name
Arch Biochem Biophysjournal_title
Archives of biochemistry and biophysicsauthors
Lewandowicz A,Jemielity J,Kańska M,Zoń J,Paneth Pdoi
10.1006/abbi.1999.1402subject
Has Abstractpub_date
1999-10-15 00:00:00pages
216-21issue
2eissn
0003-9861issn
1096-0384pii
S0003-9861(99)91402-9journal_volume
370pub_type
杂志文章abstract：:During the deglycosylation reaction of fish egg polysialoglycoproteins under the conditions of 1 M NaBH4 in 0.1 M NaOH at 37 degrees C for 48 h, a marked loss of the glycine content has been encountered, besides the serine and threonine residues to which the carbohydrate units are linked. The chemical basis behind thi...
journal_title：Archives of biochemistry and biophysics
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doi：10.1016/0003-9861(84)90590-3
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abstract：:A new enzyme homologous to phosphotriesterase was identified from the bacterium Geobacillus stearothermophilus (GsP). This enzyme belongs to the amidohydrolase family and possesses the ability to hydrolyze both lactone and organophosphate (OP) compounds, making it a phosphotriesterase-like lactonase (PLL). GsP possess...
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pub_type： 杂志文章
doi：10.1016/j.abb.2009.06.005
更新日期：2009-08-15 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2013.08.013
更新日期：2014-06-15 00:00:00
abstract：:It has been proposed that negatively charged amino acids on the surface of reductase and positively charged amino acids on the surface of P450 mediate the binding of both proteins through electrostatic interactions. In this study, we used a site-directed mutagenesis approach to determine a role for two lysine residues...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.2000.2174
更新日期：2001-01-15 00:00:00
abstract：:Aryl hydrocarbon hydroxylase activity is most closely associated with cytochrome P-450c in the rat and cytochrome P1-450 in the mouse. The sequence for the orthologous human gene coding for this enzymatic activity has been determined from several sources: cytochrome P-450c isolated from human embryonic DNA [K. Kawajir...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(87)90460-7
更新日期：1987-07-01 00:00:00
abstract：:Providing clean and affordable drinking water without harmful disinfection byproducts generated by conventional chemical disinfectants gives rise to the need for technological innovation. Nanotechnology has great potential in purifying water and wastewater treatment. A graphene oxide-silver (GO-Ag) nanocomposite with ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2016.04.018
更新日期：2016-08-15 00:00:00
abstract：:Tetrahydro-dUMP, an analog of the putative transition state in aminohydrolysis of deoxycytidine monophosphate (dCMP) inhibits the allosteric enzyme deoxycytidylate aminohydrolase with high affinity. The inhibition is reversible, and its kinetics is consistent with the analog binding at the substrate site only to one a...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1994.1138
更新日期：1994-04-01 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2020.108491
更新日期：2020-09-30 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章,评审
doi：10.1016/j.abb.2017.06.019
更新日期：2017-10-15 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2009.09.019
更新日期：2009-11-01 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1998.0728
更新日期：1998-07-15 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(84)90048-1
更新日期：1984-01-01 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(87)90374-2
更新日期：1987-11-01 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(87)90015-4
更新日期：1987-01-01 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(86)90062-7
更新日期：1986-11-15 00:00:00
abstract：:A10 smooth muscle cells, derived from embryonic rat thoracic aorta, responded to the atrial natriuretic factor (ANF) with increased levels of cyclic GMP. These cells possess high-affinity (apparent Kd = 50 pM) plasma membrane receptors for ANF. Internalization of ANF at 37 degrees C was indicated by the following: app...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(86)90504-7
更新日期：1986-08-01 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1997.0481
更新日期：1998-01-15 00:00:00
abstract：:The relationship between ligand-protein affinity and the extent of protein stabilization induced by such interactions has been investigated using the binding of polyanions to acidic fibroblast growth factor (aFGF) as a model system. It was found that the experimentally observed unfolding rate constant of aFGF consists...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1994.1080
更新日期：1994-02-15 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0037
更新日期：1996-01-15 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
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更新日期：2000-02-15 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1997.0279
更新日期：1997-10-01 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1995.1247
更新日期：1995-04-20 00:00:00
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journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2010.09.021
更新日期：2011-01-01 00:00:00
abstract：:Human lactase-phlorizin hydrolase [EC 3.2.1.23-3.2.1.62] is a disaccharidase located in the microvillus membrane of small intestinal epithelial cells. The enzyme is synthesized as a precursor protein in the endoplasmic reticulum and in addition to being glycosylated is subsequently proteolytically processed to the mat...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1995.9952
更新日期：1995-11-10 00:00:00
abstract：:Binding of ligands to the catalytic center of mammalian triosephosphate isomerase (TPI) induces a conformational change(s) that enhances the specific deamidation of Asn71 at the subunit interface. Deamidation initiates dissociation and degradation of the enzyme in vivo and in vitro. We have utilized circular dichroism...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(92)90536-6
更新日期：1992-06-01 00:00:00
abstract：:The present paper focussed on the mechanistic aspect of the reaction of singlet oxygen (1O2), in its lowest excited state (1 Delta g), toward DNA constituents. It is well known that 1O2 is able to react with the guanine moiety of DNA to produce almost specifically 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo). Howev...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2003.10.018
更新日期：2004-03-01 00:00:00
abstract：:The maximal amounts of Ca2+ being accumulated (delta Ca2+max) and H+ emitted (delta H+max) by Ca2+-loading mitochondria, with succinate (+rotenone) as respiratory substrate, were evaluated. delta Ca2+max was increased by providing either citrate or ATP to a Pi- and Mg2+-free medium. With citrate, delta H+max was only ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/0003-9861(85)90548-x
更新日期：1985-12-01 00:00:00
abstract：:hCD157 catalyzes the hydrolysis of nicotinamide riboside (NR) and nicotinic acid riboside (NAR). The release of nicotinamide or nicotinic acid from NR or NAR was confirmed by spectrophotometric, HPLC and NMR analyses. hCD157 is inactivated by a mechanism-based inhibitor, 2'-deoxy-2'-fluoro-nicotinamide arabinoside (fN...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2014.09.008
更新日期：2014-12-15 00:00:00
abstract：:Enzymes subjected to freeze-thawing are known to be protected by polymers that are preferentially excluded from the hydrated surface of proteins [reviewed in Carpenter et al. (1994) ACS Symp. Ser. 567, 134-147]. Preferentially excluded solutes are also known to stabilize quaternary structure, which enhances the thermo...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1006/abbi.1996.0337
更新日期：1996-08-15 00:00:00
abstract：:A cDNA was cloned from Ruta graveolens cells encoding a novel O-methyltransferase (OMT) with high similarity to orcinol or chavicol/eugenol OMTs, but containing a serine-rich N-terminus and a 13 amino acid insertion between motifs IV and V. Expression in Escherichia coli revealed S-adenosyl-l-methionine-dependent OMT ...
journal_title：Archives of biochemistry and biophysics
pub_type： 杂志文章
doi：10.1016/j.abb.2005.05.026
更新日期：2005-08-01 00:00:00
