Kinetic properties of chimeric class I aldehyde dehydrogenases for retinal isomers

2006 ◽  
Vol 84 (5) ◽  
pp. 799-804
Author(s):  
Hélène Brodeur ◽  
Samuel Chagnon ◽  
Maxime Parisotto ◽  
Sylvie Mader ◽  
Pangala V. Bhat

Retinal dehydrogenase type 1 (RALDH1) catalyzes the oxidation of all-trans and 9-cis retinal to the respective retinoic acids (RAs), whereas another member of the aldehyde dehydrogenase (ALDH) family, the phenobarbital-induced aldehyde dehydrogenase (PB-ALDH), is very poorly active. We have previously generated chimeras between these 2 enzymes that displayed selectivity for retinal isomers in crude bacterial extracts. Here we have characterized the kinetic properties of the corresponding purified recombinant proteins. The all-trans selective chimera RALDH-131 converted all-trans retinal to all-trans RA with 2.9-fold lower efficiency than the wild-type RALDH1 and had only residual activity with 9-cis retinal. The converse chimera PB-131 was specific for 9-cis retinal, with no residual activity for all-trans retinal. MgCl2 inhibited the activities of RALDH1 and PB-131, but not of RALDH-131, suggesting that amino acids 132–510 in RALDH are necessary for inhibition by MgCl2. These data demonstrate that the chimeric enzymes act as retinal isomer-selective ALDHs, and suggest that these enzymes may be useful to study the roles of cis RA isomers in embryogenesis and differentiation in vivo.

1978 ◽  
Vol 171 (3) ◽  
pp. 527-531 ◽  
Author(s):  
A K H MacGibbon ◽  
L F Blackwell ◽  
P D Buckley

Kinetic studies were carried out on mitochondrial aldehyde dehydrogenase (EC 1.2.1.3) isolated from sheep liver. Steady-state studies over a wide range of acetaldehyde concentrations gave a non-linear double-reciprocal plot. The dissociation of NADH from the enzyme was a biphasic process with decay constants 0.6s-1 and 0.09s-1. Pre-steady-state kinetic data with propionaldehyde as substrate could be fitted by using the same burst rate constant (12 +/- 3s-1) over a wide range of propionaldehyde concentrations. The quenching of protein fluorescence on the binding of NAD+ to the enzyme was used to estimate apparent rate constants for binding (2 × 10(4) litre.mol-1.s-1) and dissociation (4s-1). The kinetic properties of the mitochondrial enzyme, compared with those reported for the cytoplasmic aldehyde dehydrogenase from sheep liver, show significant differences, which may be important in the oxidation of aldehydes in vivo.


2019 ◽  
Vol 15 (1) ◽  
pp. 102-118 ◽  
Author(s):  
Carolina Campos-Rodríguez ◽  
José G. Trujillo-Ferrara ◽  
Ameyali Alvarez-Guerra ◽  
Irán M. Cumbres Vargas ◽  
Roberto I. Cuevas-Hernández ◽  
...  

Background: Thalidomide, the first synthesized phthalimide, has demonstrated sedative- hypnotic and antiepileptic effects on the central nervous system. N-substituted phthalimides have an interesting chemical structure that confers important biological properties. Objective: Non-chiral (ortho and para bis-isoindoline-1,3-dione, phthaloylglycine) and chiral phthalimides (N-substituted with aspartate or glutamate) were synthesized and the sedative, anxiolytic and anticonvulsant effects were tested. Method: Homology modeling and molecular docking were employed to predict recognition of the analogues by hNMDA and mGlu receptors. The neuropharmacological activity was tested with the open field test and elevated plus maze (EPM). The compounds were tested in mouse models of acute convulsions induced either by pentylenetetrazol (PTZ; 90 mg/kg) or 4-aminopyridine (4-AP; 10 mg/kg). Results: The ortho and para non-chiral compounds at 562.3 and 316 mg/kg, respectively, decreased locomotor activity. Contrarily, the chiral compounds produced excitatory effects. Increased locomotor activity was found with S-TGLU and R-TGLU at 100, 316 and 562.3 mg/kg, and S-TASP at 316 and 562.3 mg/kg. These molecules showed no activity in the EPM test or PTZ model. In the 4-AP model, however, S-TGLU (237.1, 316 and 421.7 mg/kg) as well as S-TASP and R-TASP (316 mg/kg) lowered the convulsive and death rate. Conclusion: The chiral compounds exhibited a non-competitive NMDAR antagonist profile and the non-chiral molecules possessed selective sedative properties. The NMDAR exhibited stereoselectivity for S-TGLU while it is not a preference for the aspartic derivatives. The results appear to be supported by the in silico studies, which evidenced a high affinity of phthalimides for the hNMDAR and mGluR type 1.


1991 ◽  
Vol 65 (8) ◽  
pp. 4502-4507 ◽  
Author(s):  
L P Martins ◽  
N Chenciner ◽  
B Asjö ◽  
A Meyerhans ◽  
S Wain-Hobson

1995 ◽  
Vol 60 (7) ◽  
pp. 1229-1235 ◽  
Author(s):  
Ivana Zoulíková ◽  
Ivan Svoboda ◽  
Jiří Velek ◽  
Václav Kašička ◽  
Jiřina Slaninová ◽  
...  

The vasoactive intestinal (poly)peptide (VIP) is a linear peptide containing 28 amino acid residues, whose primary structure indicates a low metabolic stability. The following VIP fragments, as potential metabolites, and their analogues were prepared by synthesis on a solid: [His(Dnp)1]VIP(1-10), VIP(11-14), [D-Arg12]VIP(11-14), [Lys(Pac)15,21,Arg20]VIP(15-22), and VIP(23-28). After purification, the peptides were characterized by amino acid analysis, mass spectrometry, RP HPLC, and capillary zone electrophoresis. In some tests, detailed examination of the biological activity of the substances in vivo and in vitro gave evidence of a low, residual activity of some fragments, viz. a depressoric activity in vivo for [His(Dnp)1]VIP(1-10) and a stimulating activity for the release of α-amylase in vitro and in vivo for [Lys(Pac)15,21,Arg20]VIP(15-22) and VIP(23-28).


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