Cytidine-2 -phosphate

Becker et al.174 find that the photoproduct of cytidine-3 -phosphate is the photohydrate. The quantum yield is dependent on the pH, and is higher for the neutral form than for the acidic form. Albert176 has published a review article on nonphotolytic hydration of the C=N bond in many heteroaromatic substances, a reaction similar in many respects to photohydration of the pyrimidines. Shapiro and Klein175 report that cytidine and cytosine are deaminated at 95°C by a variety of aqueous buffers. The reaction is pH sensitive. 

The substituents at the 5 or 6 position of the pyrimidine base have no relation to the susceptibility to RNase T2. Madison and Holley 93) have shown that RNase T2 is able to split the phosphodiester bonds of pseudouridylic acid and 5,6-dihydrouridylic acid. Recently, Saneyoshi et al. 86) have found a new minor constituent, Vp, with 5-methyl cytidine 3 -phosphate and other mononucleotides on the two-dimensional paper chromatogram of RNase T2 exhaustive digest of E. coli tRNAVal later the structure of V was proved to be uridine-5-oxyacetic acid 94). 

A good source of uncommon bases is tRNA. It provides substrates for studying the effect of base on the rate of hydrolysis. Baev et al. (62) showed that V2-dimethylguanylyl-(3 -5 )-cytidine-3 phosphate (G2m-pCp) was hydrolyzed much slower than the usual GpCp. Venkstern (63) reported that Tp was hydrolyzed very slowly. Naylor et al. (64) found that Cp was hydrolyzed with half the rate of CpU. The same group of workers introduced (64, 65) a chemical block on uridine and pseudo-uridine residues by reacting RNA with l-cyclohexyl-3-(2-morpho-liny]-(4)-ethyl)-carbodiimide metho-p-toluene sulfonate. The modification of the uridine residues completely blocked the action of venom exonuclease and also blocked the action of pancreatic RNase. 

RNase A is completely inhibited if either of two histidine residues (His 12 or His 119) is modified by car-boxymethylation with iodoacetate (fig. 8.13) suggesting that these histidines play important roles in the active site. In support of this conclusion, the reaction of iodoacetate with His 12 or His 119 is inhibited by cytidine-3 -phosphate and other small molecules that bind at the active site. Lysine 41 has been implicated similarly in the active site by the observation that enzymatic activity is destroyed by the reaction of... 

Box HC (1977) Radiation effects ESR and ENDOR Analysis. Academic Press, New York Box HC, Budzinski EE (1975) Primary radiation damage in thymidine. J Chem Phys 62 197-199 Box HC, Potter WR, Budzinski EE (1975) The reduction of nucleotides by ionizing radiation Uridine 5 phosphate and cytidine 3 phosphate. J Chem Phys 62 3476-3478 Box HC, Budzinski EE, Freund HG, Evans MS, Patrzyc HB, Wallace JC, Maccubbin AE (1993) Vicinal lesions in X-irradiated DNA Int J Radiat Biol 64 261-263 Box HC, Freund HG, Budzinski EE, Wallace JC, Maccubbin AE (1995) Free radical-induced double base lesions. Radiat Res 141 91-94... 

Fig. 17.11. a Uridine-3 -phosphate H20 [URIDMP10] b cytidine-3 -phosphate (monoclinic) [CYTIAC01],, intramolecular... 

The crystal structure of cytidine-3 -phosphate (monoclinic) [CYTIAC01]... 

CYTIAC. Cytidine 3 -phosphate (orthorhombic form) cytidylic acid B (C9H14N308P). Sundaral-ingam M, Jensen LH (1965) J Mol Biol 13 914... 

Properties (Cytidine-3 -phosphate) White, crystalline powder odorless mild sour taste. Mp crystals from 50% alcohol 230-233C (with decomposition) crystals from water 227C (with decomposition). Slightly soluble in water and dilute alkalies insoluble in alcohol and other organic solvents. 

Treatment of (152) with 2-cyanoethyl phosphate and A, A -dicyclo-hexylcarbodiimide in pyridine yielded the diester (153) which was converted by 7 iV ammonium hydroxide (at 60° for 3 hours) into cytidine 2 -phosphate (154), exclusively. When this procedure was performed with the 2, 5 -dibenzoate (155), cytidine 3 -phosphate (157) was obtained, along with about 20% of the 2 -phosphate (154). It is clear that, in the reaction of (153) to give (154), 2-cyanoethyl elimination [see Scheme 3 (77)— (78)] preceded debenzoylation this accounts for the fact that (154) was obtained without contamination by cytidine 3 -phosphate. In the reaction (156)- (1S7), the authors suggested that some debenzoyla-... 

Under basic conditions (0.2 M barium hydroxide, 100°, 30 minutes), the nucleoside 3 5 -cycIic phosphates are converted into the 3 - and 5 -phosphates in the ratio of about 5 1. For cytidine 3 5 -cyclic phosphate, some concomitant deamination to the uridine nucleotide analogs is also observed (as noted with cytidine 3 -phosphate), so that the nucleotides obtained are similar to those found in the alkaline hydrolyzate of uridine 3 5 -cyclic phosphate. In addition, one of the nucleotides obtained in these hydrolyzates differs from the 3 - or 5 -phosphates in its ion-exchange chromatographic behavior. The presence of an unidentified nucleoside monophosphate in small proportion was also observed when 2 -deoxy-cytidine 3 5 -cyclic phosphate was hydrolyzed with barium hydroxide under similar conditions. 

Cy tidy lie Acid. Cyridine-3 -monophosphate cytidylic acid b 3 -cytidinephosphoric acid cytidine-3 -phosphate 3 -cytosylic acid 3 -CMP, CjH NjOjP mol wt 323.19. C 33.44% H 4-37%, N 13.00%, O 39-61%. P 9 58% Ribonuclease inhibitor. Prepn from yeast ribonucleic acid see refs under 2 -Cytidylic Acid. Prepn by pancreatic-ribonuclease-catalyzed ring opening of dicyclohexy] -guanidinium cytidine 2 ,3 -cyclic phosphate Lohrmann,... 

However, on the other hand the mechanism proposed here may be specific only for photohydration of uracil and the 1-alkyluracils examined. The lack of pH dependence in photohydration of dimethyluracil, the failure of thymine to form a photohydrate even at low pH values (4), and the recent observation that cytidine-3 -phosphate hydrates faster at neutral pH values than at acid pH values (2), suggest that the fastest... 

Methylcytidine (correction to previous paper), platinum complex of cytidine 3 -phosphate, l- 3-D-arabinofuranosylcytosine 5 -phosphate (2 independent analyses), 2,2 -anhydro-l-/3-D-arabinofuranosyl-5-dimethylsulphonio-6-oxocytosine chloride, 2,2 -anhydro-l-(3, 5 -di-0-acetyl-j3-D-arabinofuranosyl)-5-chloro - 6 - oxocy tosine, 2,l -anhy dro -1 - - D -arabinofuranosylcy tosine 2 5 -diphosphate, and 6,2 -anhydro-1 - 3-D-arabinofuranosyl-6-hydroxycytosine. Adenosine 5 -triphosphate disodium salt, adenosine 5 -methylphosphate, adenosine 5-methylphosphonate, 8-methyladenosine 3-phosphate, 2-aza-adenosine, 9-ce-D-arabinofuranosyladenine, 8,2 -anhydro-9- 3-D-arabino-... 

Some of the facts mentioned above can be illustrated by discussing the hydrolysis of the dinucleotide, 5 (2 or 3 ) guanylyl) cytidine 3 phosphate (XII). 

This compound has been isolated after subjecting yeast ribonucleic acid to brief acid hydrolysis. When it is treated with alkali there is cleavage at (1), with the formation and subsequent hydrolysis of a cyclic anhydride of guanylic acid. The final products are guanosine-2 -phosphate, guanosine-3 -phosphate, and cytidine-3 -phosphate. The last two would be split by 3-nucleotidase from barley. 

CjHsOj]- X-irr. of cytidine-3 -phosphate at ENDOR, 2.0048 Conformation I 76Ber5... 

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