The HELLGH Motif of Rat Liver Dipeptidyl Peptidase III Is Involved in Zinc Coordination and the Catalytic Activity of the Enzyme

Biochemistry ◽  
1999 ◽  
Vol 38 (26) ◽  
pp. 8299-8303 ◽  
Author(s):  
Katsuhiko Fukasawa ◽  
Kayoko M. Fukasawa ◽  
Hiroyuki Iwamoto ◽  
Junzo Hirose ◽  
Minoru Harada
Keyword(s):  
Catalytic Activity ◽  
Rat Liver ◽  
Dipeptidyl Peptidase ◽  
Zinc Coordination

Eritadenines - Novel type of potent inhibitors of S-adenosyl-L-homocysteine hydrolase

1982 ◽  
Vol 47 (1) ◽  
pp. 167-172 ◽  
Author(s):  
Ivan Votruba ◽  
Antonín Holý
Keyword(s):  
Catalytic Activity ◽  
Rat Liver ◽  
Hydrolytic Reaction

Rat liver SAH-hydrolase is strongly inhibited by four stereoisomeric 4-(adenin-9-yl)-2,3-dihydroxybutyric acids (eritadenines). D-Eritadenine, which is the most effective of the four, inactivates the catalytic activity of SAH-hydrolase at IC50 = 1.2 .10-8 mol l-1 in the hydrolytic reaction. The enzyme is irreversibly inhibited (τ/2 = 1.6 min). The inactivation activity decreases in the order D-erythro(2R, 3R) L-erythro(2S, 3S) threo(2S, 3R) threo(2R, 3S) configuration.

Purification and Characterization of Dipeptidyl Peptidase IV in Rat Liver Lysosomal Membranes1

1992 ◽  
Vol 111 (6) ◽  
pp. 770-777 ◽  
Author(s):  
Takahiro Kyouden ◽  
Masaru Himeno ◽  
Toyoko Ishikawa ◽  
Yukihide Ohsumi ◽  
Keitaro Kato
Keyword(s):  
Rat Liver ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Purification And Characterization

Characterization of the Metal-Substituted Dipeptidyl Peptidase III (Rat Liver)†

Biochemistry ◽  
2001 ◽  
Vol 40 (39) ◽  
pp. 11860-11865 ◽  
Author(s):  
Junzo Hirose ◽  
Hiroyuki Iwamoto ◽  
Ikuko Nagao ◽  
Kanako Enmyo ◽  
Hidenori Sugao ◽  
...  
Keyword(s):  
Rat Liver ◽  
Dipeptidyl Peptidase

scholarly journals Removal of an N-terminal peptide from mitochondrial aspartate aminotransferase abolishes its interactions with mitochondria in vitro

1985 ◽  
Vol 228 (3) ◽  
pp. 609-614 ◽  
Author(s):  
K M O'Donovan ◽  
S Doonan ◽  
E Marra ◽  
S Passarella ◽  
E Quagliariello
Keyword(s):  
Catalytic Activity ◽  
Rat Liver ◽  
Aspartate Aminotransferase ◽  
Terminal Segment ◽  
Model System ◽  
Native Enzyme ◽  
Cysteine Residues ◽  
Native Form ◽  
Mitochondrial Aspartate Aminotransferase

Treatment of mitochondrial aspartate aminotransferase from rat liver with trypsin leads to specific cleavage of the bonds between residues 26 and 27, and residues 31 and 32. The proteolysed enzyme has only a small residual catalytic activity, but retains a conformation similar to that of the native form as judged by accessibility and reactivity of cysteine residues. Proteolysis abolishes the ability of the enzyme either to bind to mitochondria or to be imported into the organelles. This suggests that the N-terminal segment of the native enzyme is essential for both of these functions, at least in the model system used to study the import process.

scholarly journals Molecular cloning and heterologous expression of a cDNA encoding a mouse glutathione S-transferase Yc subunit possessing high catalytic activity for aflatoxin B1-8,9-epoxide

1992 ◽  
Vol 285 (1) ◽  
pp. 173-180 ◽  
Author(s):  
J D Hayes ◽  
D J Judah ◽  
G E Neal ◽  
T Nguyen
Keyword(s):  
Catalytic Activity ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Rat Liver ◽  
Cdna Clone ◽  
Aflatoxin B1 ◽  
Mouse Liver ◽  
High Catalytic Activity ◽  
Glutathione S Transferase ◽  
E Coli

Resistance to the carcinogenic effects of aflatoxin B1 (AFB1) in the mouse is due to the constitutive expression of an Alpha-class glutathione S-transferase (GST), YcYc, with high detoxification activity towards AFB1-8,9-epoxide. A cDNA clone (pmusGST Yc) for a murine GST Yc polypeptide has been isolated. Sequencing has shown the cDNA insert of pmusGST Yc to be 922 bp in length, with an open reading frame of 663 bp that encodes a polypeptide of M(r) 25358. The primary structure of the murine GST Yc subunit predicted by pmusGST Yc is in complete agreement with the partial amino acid sequence of the aflatoxin-metabolizing mouse liver GST described previously [McLellan, Kerr, Cronshaw & Hayes (1991) Biochem. J. 276, 461-469]. A plasmid, termed pKK-musGST Yc, which permits the expression of the murine Yc subunit in Escherichia coli, has been constructed. The murine GST expressed in E. coli was purified and found to be catalytically active towards several GST substrates, including AFB1-8,9-epoxide. This enzyme was also found to possess electrophoretic and immunochemical properties closely similar to those of the GST Yc subunit from mouse liver. However, the GST synthesized in E. coli and the constitutive mouse liver Alpha-class GST exhibited small differences in their chromatographic behaviour during reverse-phase h.p.l.c. Automated Edman degradation revealed alanine to be the N-terminal amino acid in the GST Yc subunit expressed in E. coli, whereas the enzyme in mouse liver possesses a blocked N-terminus. Although sequencing showed that the purified Yc subunit from E. coli lacked the initiator methionine, the amino acid sequence obtained over the first eleven N-terminal residues agreed with that predicted from the cDNA clone, pmusGST Yc. Comparison of the deduced amino acid sequence of the mouse Yc polypeptide with the primary structures of the rat Alpha-class GST enzymes revealed that it is more closely related to the ethoxyquin-induced rat liver Yc2 subunit than to the constitutively expressed rat liver Yc1 subunit. The significance of the fact that both mouse Yc and rat Yc2 exhibit high catalytic activity towards AFB1-8,9-epoxide, whereas rat Yc1 possesses little activity towards this compound, is discussed in terms of structure/function.

scholarly journals Evidence for a role of dipeptidyl peptidase IV in fibronectin-mediated interactions of hepatocytes with extracellular matrix

1989 ◽  
Vol 262 (1) ◽  
pp. 327-334 ◽  
Author(s):  
G A Piazza ◽  
H M Callanan ◽  
J Mowery ◽  
D C Hixson
Keyword(s):  
Extracellular Matrix ◽  
Cell Surface ◽  
Rat Liver ◽  
Tissue Transglutaminase ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Type I ◽  
Cell Surface Glycoprotein ◽  
Dpp Iv ◽  
Fibronectin Binding

Dipeptidyl peptidase IV (DPP IV) is a cell surface glycoprotein which has been implicated in hepatocyte-extracellular matrix interactions [Hixson, DeLourdes, Ponce, Allison & Walborg (1984) Exp. Cell Res. 152, 402-414; Walborg, Tsuchida, Weeden, Thomas, Barrick, McEntire, Allison & Hixson (1985) Exp. Cell Res. 158, 509-518; Hanski, Huhle & Reutter (1985) Biol. Chem. Hoppe-Seyler 366, 1169-1176]. However, its proteolytic substrate(s) and/or binding protein(s) which mediate this influence have not been conclusively identified. Nitrocellulose binding assays using 125I-labelled DPP IV that was purified to homogeneity from rat hepatocytes revealed a direct interaction of DPP IV with fibronectin. Although fibronectin could mediate an indirect binding of DPP IV to collagen, no evidence was found for a direct binding of DPP IV to native or denatured Type I collagen. Fibronectin appeared to bind DPP IV at a site distinct from its exopeptidase substrate recognition site since protease inhibitors such as competitive peptide substrates and phenylmethanesulphonyl fluoride enhanced binding, possibly as a result of an altered conformation of DPP IV. To determine if fibronectin binding to DPP IV is involved in the interaction of fibronectin with the hepatocyte surface, the effect of various DPP IV inhibitors on 125I-fibronectin binding to isolated hepatocytes in suspension was examined. Kinetic studies revealed that inhibitors of DPP IV which enhanced fibronectin binding in vitro accelerated the initial binding of fibronectin to the cell surface where it was subsequently cross-linked (presumably by tissue transglutaminase) to as yet undefined components. Immunolocalization of fibronectin and DPP IV in normal rat liver sections showed that both proteins were present along the hepatocyte sinusoidal membrane. These observations, coupled with previous results showing that DPP IV is tightly bound to biomatrix isolated from rat liver (Hixson et al., 1984; Walborg et al., 1985), suggest that DPP IV binding to fibronectin may play a role in interactions of hepatocytes with extracellular matrix in vivo and possibly in matrix assembly.

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