Characterization of Substrate Specificity of Dog CYP1A2 Using CYP1A2-Deficient and Wild-Type Dog Liver Microsomes

2008 ◽  
Vol 36 (9) ◽  
pp. 1903-1908 ◽  
Author(s):  
Masashi Mise ◽  
Takanori Hashizume ◽  
Setsuko Komuro
Keyword(s):  
Substrate Specificity ◽  
Liver Microsomes ◽  
Wild Type ◽  
Dog Liver

scholarly journals The characterization of glutathione S-transferases from rat olfactory epithelium

1993 ◽  
Vol 290 (1) ◽  
pp. 199-204 ◽  
Author(s):  
K K Banger ◽  
E A Lock ◽  
C J Reed
Keyword(s):  
Substrate Specificity ◽  
Olfactory Epithelium ◽  
Liver Microsomes ◽  
Subunit Composition ◽  
Reverse Phase ◽  
Glutathione S Transferases ◽  
Gst Activity

The glutathione S-transferases (GSTs) of rat olfactory epithelium have been characterized with regard to substrate specificity and subunit composition and compared to those of the liver. The presence of cytosolic GST activity in rat olfactory epithelium was confirmed and, using 1-chloro-2,4-dinitrobenzene as substrate, was found to be approximately one-third that of the liver. Olfactory microsomal GST activity was greater than that of liver microsomes and could be activated by treatment with the sulphydryl agent N-ethylmaleimide. The subunit and isoenzyme profile of GSTs in the olfactory epithelium was investigated using a number of techniques. (1) Olfactory GSTs were characterized using a range of relatively subunit-specific substrates. Activities ranged from 40-90% of those found in liver. Most noticeable was the extremely low olfactory activity with the substrate specific for subunit 1. (2) Immunoblotting with antibodies against specific rat hepatic GSTs confirmed the presence of a number of subunits and the absence of subunit 1. (3) F.p.l.c. chromatofocusing and reverse-phase h.p.l.c. indicated that the cytosolic GST profile of olfactory epithelium is unique and is made up of subunits 2, 3, 4, 7, 8 and 11 with subunits 3 and 4 predominating. There is an absence of isoenzymes containing subunit 1.

scholarly journals L-Phenylalanine Transport in Saccharomyces cerevisiae: Participation of GAP1, BAP2, and AGP1

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Daniel A. Sáenz ◽  
Mónica S. Chianelli ◽  
Carlos A. Stella
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Substrate Specificity ◽  
Nitrogen Source ◽  
Type Strain ◽  
Wild Type Strain ◽  
Ammonium Ion ◽  
Wild Type ◽  
Synthetic Media ◽  
Phenylalanine Transport

We focused on the participation of GAP1, BAP2, and AGP1 in L-phenylalanine transport in yeast. In order to study the physiological functions of GAP1, BAP2, and AGP1 in L-phenylalanine transport, we examined the kinetics, substrate specificity, and regulation of these systems, employing isogenic haploid strains with the respective genes disrupted individually and in combination. During the characterization of phenylalanine transport, we noted important regulatory phenomena associated with these systems. Our results show that Agp1p is the major transporter of the phenylalanine in a gap1 strain growing in synthetic media with leucine present as an inducer. In a wild type strain grown in the presence of leucine, when ammonium ion was the nitrogen source, Bap2p is the principal phenylalanine carrier.

Functional characterization of the H+/K+ ATPase in wild type and gastrin knock-out mice

2007 ◽  
Vol 45 (05) ◽  
Author(s):  
A Schnur ◽  
P Hegyi ◽  
V Venglovecz ◽  
Z Rakonczay ◽  
I Ignáth ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Wild Type ◽  
Knock Out ◽  
Knock Out Mice

scholarly journals Kinetic characterization of yeast alcohol dehydrogenases. Amino acid residue 294 and substrate specificity.

1987 ◽  
Vol 262 (8) ◽  
pp. 3754-3761
Author(s):  
A.J. Ganzhorn ◽  
D.W. Green ◽  
A.D. Hershey ◽  
R.M. Gould ◽  
B.V. Plapp
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Amino Acid Residue ◽  
Kinetic Characterization ◽  
Alcohol Dehydrogenases

Characterization of a novel moderate-substrate specificity amino acid racemase from the hyperthermophilic archaeon Thermococcus litoralis

2021 ◽  
Author(s):  
Ryushi Kawakami ◽  
Chinatsu Kinoshita ◽  
Tomoki Kawase ◽  
Mikio Sato ◽  
Junji Hayashi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Enzyme Stability ◽  
Hyperthermophilic Archaea ◽  
Thermococcus Litoralis ◽  
Hyperthermophilic Archaeon ◽  
Aminobutyrate Aminotransferase ◽  
Chaperone Protein ◽  
Amino Acid Racemase

Abstract The amino acid sequence of the OCC_10945 gene product from the hyperthermophilic archaeon Thermococcus litoralis DSM5473, originally annotated as γ-aminobutyrate aminotransferase, is highly similar to that of the uncharacterized pyridoxal 5ʹ-phosphate (PLP)-dependent amino acid racemase from Pyrococcus horikoshii. The OCC_10945 enzyme was successfully overexpressed in Escherichia coli by co-expression with a chaperone protein. The purified enzyme demonstrated PLP-dependent amino acid racemase activity primarily toward Met and Leu. Although PLP contributed to enzyme stability, it only loosely bound to this enzyme. Enzyme activity was strongly inhibited by several metal ions, including Co2+ and Zn2+, and non-substrate amino acids such as l-Arg and l-Lys. These results suggest that the underlying PLP-binding and substrate recognition mechanisms in this enzyme are significantly different from those of the other archaeal and bacterial amino acid racemases. This is the first description of a novel PLP-dependent amino acid racemase with moderate substrate specificity in hyperthermophilic archaea.

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