scholarly journals Cyclic Purine and Pyrimidine Nucleotides Bind to the HCN2 Ion Channel and Variably Promote C-Terminal Domain Interactions and Opening

Structure ◽  
2016 ◽  
Vol 24 (10) ◽  
pp. 1629-1642 ◽  
Author(s):  
Leo C.T. Ng ◽  
Igor Putrenko ◽  
Victoria Baronas ◽  
Filip Van Petegem ◽  
Eric A. Accili
Keyword(s):  
Ion Channel ◽  
Pyrimidine Nucleotides ◽  
Terminal Domain ◽  
Domain Interactions ◽  
Purine And Pyrimidine Nucleotides

scholarly journals Substrate Specificity of the FurE Transporter Is Determined by Cytoplasmic Terminal Domain Interactions

Genetics ◽  
2017 ◽  
pp. genetics.300327.2017 ◽  
Author(s):  
Georgia F. Papadaki ◽  
Sotiris Amillis ◽  
George Diallinas
Keyword(s):  
Substrate Specificity ◽  
Terminal Domain ◽  
Domain Interactions

scholarly journals Purification and some properties of an IMP-specific 5′-nucleotidase from yeast

1994 ◽  
Vol 298 (3) ◽  
pp. 593-598 ◽  
Author(s):  
R Itoh
Keyword(s):  
Molecular Mass ◽  
Substrate Concentration ◽  
Soluble Protein ◽  
The Other ◽  
Metal Salts ◽  
Bivalent Metal ◽  
Pyrimidine Nucleotides ◽  
Ph Optimum ◽  
A Subunit ◽  
Purine And Pyrimidine Nucleotides

An IMP-hydrolysing enzyme was purified to homogeneity from yeast extract. It was a soluble protein with an apparent molecular mass of 220 kDa, with a subunit molecular mass of 55 kDa. It was highly specific for IMP, and there was virtually no detectable activity with the other purine and pyrimidine nucleotides tested, including AMP and dIMP. The enzyme had a pH optimum of 6.0-6.5. Its activity was absolutely dependent on bivalent metal salts: Mg2+ was most potent, followed by Co2+ and Mn2+. The velocity/substrate-concentration plot of the enzyme was slightly sigmoidal (h = 1.7) and the s0.5 was 0.4 mM. ATP stimulated the enzyme by decreasing both h and s0.5. Diadenosine tetraphosphate stimulated the enzyme as effectively as ATP. Although the properties of the enzyme are similar to those of the IMP/GMP 5′-nucleotidase identified in various animals [Itoh (1993) Comp. Biochem. Physiol. 105B, 13-19], the substrate specificity of the former was much more strict than the latter.

scholarly journals Differential Inhibition of Adenylyl Cyclase Isoforms and Soluble Guanylyl Cyclase by Purine and Pyrimidine Nucleotides

2004 ◽  
Vol 279 (19) ◽  
pp. 19955-19969 ◽  
Author(s):  
Andreas Gille ◽  
Gerald H. Lushington ◽  
Tung-Chung Mou ◽  
Michael B. Doughty ◽  
Roger A. Johnson ◽  
...  
Keyword(s):  
Adenylyl Cyclase ◽  
Guanylyl Cyclase ◽  
Cell Membranes ◽  
Hydrophobic Interactions ◽  
Soluble Guanylyl Cyclase ◽  
Competitive Inhibitor ◽  
Pyrimidine Nucleotides ◽  
Catalytic Subunits ◽  
Edema Factor ◽  
Purine And Pyrimidine Nucleotides

Mammals express nine membranous adenylyl cyclase isoforms (ACs 1–9), a structurally related soluble guanylyl cyclase (sGC) and a soluble AC (sAC). Moreover,Bacillus anthracisandBacillus pertussisproduce the AC toxins, edema factor (EF), and adenylyl cyclase toxin (ACT), respectively. 2′(3′)-O-(N-methylanthraniloyl)-guanosine 5′-[γ-thio]triphosphate is a potent competitive inhibitor of AC in S49 lymphoma cell membranes. These data prompted us to study systematically the effects of 24 nucleotides on AC in S49 and Sf9 insect cell membranes, ACs 1, 2, 5, and 6, expressed in Sf9 membranes and purified catalytic subunits of membranous ACs (C1 of AC5 and C2 of AC2), sAC, sGC, EF, and ACT in the presence of MnCl2.N-Methylanthraniloyl (MANT)-GTP inhibited C1·C2 with aKiof 4.2 nm. Phe-889 and Ile-940 of C2 mediate hydrophobic interactions with the MANT group. MANT-inosine 5′-[γ-thio]triphosphate potently inhibited C1·C2 and ACs 1, 5, and 6 but exhibited only low affinity for sGC, EF, ACT, and G-proteins. Inosine 5′-[γ-thio]triphosphate and uridine 5′-[γ-thio]triphosphate were mixed G-protein activators and AC inhibitors. AC5 was up to 15-fold more sensitive to inhibitors than AC2. EF and ACT exhibited unique inhibitor profiles. At sAC, 2′,5′-dideoxyadenosine 3′-triphosphate was the most potent compound (IC50, 690 nm). Several MANT-adenine and MANT-guanine nucleotides inhibited sGC withKivalues in the 200–400 nmrange. UTP and ATP exhibited similar affinities for sGC as GTP and were mixed sGC substrates and inhibitors. The exchange of MnCl2against MgCl2reduced inhibitor potencies at ACs and sGC 1.5–250-fold, depending on the nucleotide and cyclase studied. The omission of the NTP-regenerating system from cyclase reactions strongly reduced the potencies of MANT-ADP, indicative for phosphorylation to MANT-ATP by pyruvate kinase. Collectively, AC isoforms and sGC are differentially inhibited by purine and pyrimidine nucleotides.

Septin C-Terminal Domain Interactions: Implications for Filament Stability and Assembly

2011 ◽  
Vol 62 (2) ◽  
pp. 317-328 ◽  
Author(s):  
Ivo Almeida Marques ◽  
Napoleão Fonseca Valadares ◽  
Wanius Garcia ◽  
Julio Cesar Pissuti Damalio ◽  
Joci Neuby Alves Macedo ◽  
...  
Keyword(s):  
Terminal Domain ◽  
Domain Interactions
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