New pyrimidine (uridine) specific cyclizing 2'-ribonucleotidyltransferase and nonspecific decyclizing 2',3'-phosphodiesterase

1979 ◽  
Vol 44 (3) ◽  
pp. 957-975 ◽  
Author(s):  
Antonín Holý ◽  
Ivan Rosenberg
Keyword(s):  
Alkyl Esters ◽  
Native State ◽  
Heterocyclic Base ◽  
Pancreatic Ribonuclease ◽  
Sugar Moiety ◽  
High Preference ◽  
Alkyl Moiety ◽  
Cyclic Phosphate ◽  
Sepharose 4B ◽  
Cyclic Phosphates

Chromatography of an aqueous extract of rape seedlings on modified Cellex P, followed by chromatography on two types of modified Sepharose 4B, afforded two nucleolytic activities which split ribonucleoside 2',3'-cyclic phosphates. The first enzyme (C1) affording 2'-nucleotides on splitting, was characterized as a decyclizing 2',3'-phosphodiesterase, nonspecific towards the nature of the heterocyclic base. The second enzyme (D2) splits uridine 2',3'-cyclic phosphate and cytidine 2',3'-cyclic phosphate with high preference for the uridine derivative, its specificity towards the heterocyclic base and the sugar moiety resembling that of pancreatic ribonuclease. The products are in both cases 3'-ribonucleotides. The enzyme splits also alkyl esters of uridine 3'-phosphate with the intermediary formation of uridine 2',3'-cyclic phosphate. The splitting rate decreases with growing alkyl moiety. This enzyme is classified as a new pyrimidine specific cyclizing 2-ribonucleotidyltransferase (EC 2.7.7). Both enzymes were isolated free of other nucleolytic activities. In the native state they are stabilized by an acidic protein.

The effect of acceptor modification upon the synthesis of dinucleoside phosphates catalyzed by non-specific ribonucleases of Penicillium claviforme

1979 ◽  
Vol 44 (2) ◽  
pp. 613-625 ◽  
Author(s):  
Valentina I. Gulyaeva ◽  
Antonín Holý
Keyword(s):  
Reaction Center ◽  
Hydroxy Group ◽  
Pyrimidine Ring ◽  
Phosphate Group ◽  
Mutual Orientation ◽  
Acceptor Molecule ◽  
Heterocyclic Base ◽  
Sugar Moiety ◽  
Cyclic Phosphate ◽  
Penicillium Claviforme

The present paper studies the effect of the modification of heterocyclic base, sugar moiety and the presence of phosphate group on the nucleoside acceptors in the synthesis of dinucleoside phosphates from adenosine 2',3'-cyclic phosphate as donor, catalyzed by nonspecific acidic extracellular and intracellular ribonucleases from Penicillium claviforme. The enzyme binds specifically the acceptor molecule, preferring cytosine nucleosides. It requires the presence of the whole sugar moiety, an exact mutual orientation of the heterocyclic base and the reaction center (5'-hydroxy group), and a suitable conformation of the acceptor molecule. The enzyme-acceptor bond is homochiral and the presence of the N3-H group in the pyrimidine ring is important. The reaction between the donor and the acceptor is bimolecular and is competitively inhibited by some purine nucleosides.

A synthetic study on cyclic phosphate derivatives of seconucleosides as potential antiviral agents (II): Synthesis of 3′, 5′-cyclic phosphates of 6-aza-2′-azido-secouridine

1992 ◽  
Vol 15 (4) ◽  
pp. 343-346
Author(s):  
Dae Hong Shin ◽  
Jae-Wook Yang ◽  
Joong Hyup Kim ◽  
Chong-Kyo Lee ◽  
Won-Keun Chung ◽  
...  
Keyword(s):  
Antiviral Agents ◽  
Cyclic Phosphate ◽  
Cyclic Phosphates ◽  
Derivatives Of

scholarly journals The nonenzymatic template-directed ligation of oligonucleotides

2006 ◽  
Vol 3 (3) ◽  
pp. 243-249 ◽  
Author(s):  
A. V. Lutay ◽  
E. L. Chernolovskaya ◽  
M. A. Zenkova ◽  
V. V. Vlassov
Keyword(s):  
Metal Ion ◽  
Divalent Cations ◽  
Bound Water ◽  
Transesterification Reaction ◽  
Water Molecules ◽  
Pka Values ◽  
Rna Molecules ◽  
High Reaction ◽  
Cyclic Phosphate ◽  
Cyclic Phosphates

Abstract. The nonenzymatic template-directed ligation of oligonucleotides containing 2', 3'-cyclic phosphate was investigated in the presence of divalent cations. Ligation of the oligonucleotides readily occurred in the presence of Mg2+, Mn2+, Co2+, Zn2+, Pb2+. Efficacy of the metal ion catalysts inversely correlated with pKa values of the metal-bound water molecules. The intermolecular transesterification reaction yielded at least 95metal ion. Relatively high reaction yields (up to 15fragmentation to oligonucleotides with 2',3'-cyclic phosphates, followed by reactions of those oligonucleotides could provide a source of new RNA molecules under prebiotic conditions.

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