Estimation of Nucleic Acids

Volkin, Elliot; Cohn, Waldo E.

doi:10.1002/9780470110171.ch11

Cited by 342 publications

(29 citation statements)

References 64 publications

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“…Extraction and estimation of RNA RNA was extracted using 200 mg fresh endosperms and embryo axes samples at different hours of germination of seeds according to the method of Volkin and Cohn (1954) as modified by Mittal and Dubey (1991). Estimation of RNA was done using orcinol reagent (Schneider 1957).…”

Section: Plant Materialsmentioning

confidence: 99%

Inhibition of ribonuclease and protease activities in germinating rice seeds exposed to nickel

Maheshwari

Dubey

2008

Acta Physiol Plant

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When the seeds of two rice cvs. Malviya-36 and Pant-12 were germinated up to 120 h in the presence of 200 and 400 lM NiSO 4 , a significant reduction in the germination of seeds occurred. Seeds germinating in the presence of 400 lM NiSO 4 showed about 12-20% decline in germination percent, about 20-53% decline in lengths and about 8-34% decline in fresh weights of roots and shoots at 120 h of germination. Ni 2+ exposure of germinating seeds resulted in apparent increased levels of RNA, soluble proteins, and free amino acids in endosperms as well as embryo axes. A 400 lM Ni 2+ treatment led to about 58-101% increase in the level of soluble proteins and about 39-107% increase in the level of free amino acids in embryo axes at 96 h of germination. Activities of ribonuclease and protease declined significantly with increasing levels of Ni 2+ treatment. Isoenzyme profile of RNase as revealed by activity staining indicated decline in the intensities of 3-4 preexisting enzyme isoforms in embryo axes of both the rice cultivars and disappearance of one of the two isoforms in endosperms of cv. Pant-12 due to 400 lM Ni 2+ treatment. Results suggest that the presence of high level of Ni 2+ in the medium of germinating rice seeds serves as a stress factor resulting in decreased hydrolysis as well as delayed mobilization of endospermic RNA and protein reserves and causing imbalance in the level of biomolecules like RNA, proteins, and amino acids in growing embryo axes. These events would ultimately contribute to decreased germination of rice seeds in high Ni 2+ containing environment.

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Section: Plant Materialsmentioning

confidence: 99%

Inhibition of ribonuclease and protease activities in germinating rice seeds exposed to nickel

Maheshwari

Dubey

2008

Acta Physiol Plant

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“…Under these chromatographic conditions the following nucleotides eluted in the order: S-inosylhomocysteine (SIH) at 10.8 min, inosine at 12.3 min, S-adenosylhomocysteine (SAH) at 14.5 min, 5=-dI at 16 min, adenosine (Ad) at 17.2 min, 5=-dA at 20 min, methylthioinosine (MTI) at 22 min, and 5=-methylthioadenosine (MTA) at 26 min. Quantitation was based on absorbance at 260 nm for the adenosine-and 248 nm for the inosine-containing compounds using ε 260 ϭ 14,900 M Ϫ1 cm Ϫ1 for adenosine and ε 250 ϭ 12,300 M Ϫ1 cm Ϫ1 for inosine (8). The chromatographic separation of 5=-dA and 5=-dI was also performed on the same Shimadzu HPLC System with a Phenomex Kinetex (C 18 reverse-phase column, 100 by 4.6 mm, 2.6-m particle size) with an elution profile that consisted of 1 min at 98% sodium acetate buffer and 2% methanol, followed by a linear gradient to 70% sodium acetate buffer-30% methanol for 19 min and then another linear gradient to 20% sodium acetate buffer-80% methanol for 5 min, followed by an isocratic flow at 20% sodium acetate buffer-80% methanol for 5 min at 0.5 ml/ min.…”

Section: Methodsmentioning

confidence: 99%

Identification of a 5'-Deoxyadenosine Deaminase in Methanocaldococcus jannaschii and Its Possible Role in Recycling the Radical S-Adenosylmethionine Enzyme Reaction Product 5'-Deoxyadenosine

Miller¹,

O’Brien²,

Xu³

et al. 2013

Journal of Bacteriology

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We characterize here the MJ1541 gene product from Methanocaldococcus jannaschii, an enzyme that was annotated as a 5=-methylthioadenosine/S-adenosylhomocysteine deaminase (EC 3.5.4.31/3.5.4.28). The MJ1541 gene product catalyzes the conversion of 5=-deoxyadenosine to 5=-deoxyinosine as its major product but will also deaminate 5=-methylthioadenosine, S-adenosylhomocysteine, and adenosine to a small extent. On the basis of these findings, we are naming this new enzyme 5=-deoxyadenosine deaminase (DadD). The K m for 5=-deoxyadenosine was found to be 14.0 ؎ 1.2 M with a k cat /K m of 9.1 ؋ 10 9 M ؊1 s ؊1 . Radical S-adenosylmethionine (SAM) enzymes account for nearly 2% of the M. jannaschii genome, where the major SAM derived products is 5=-deoxyadenosine. Since 5=-dA has been demonstrated to be an inhibitor of radical SAM enzymes; a pathway for removing this product must be present. We propose here that DadD is involved in the recycling of 5=-deoxyadenosine, whereupon the 5=-deoxyribose moiety of 5=-deoxyinosine is further metabolized to deoxyhexoses used for the biosynthesis of aromatic amino acids in methanogens.

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“…The RNA content of microsomal albumin, based on the determination of ribose by the orcinol procedure (Volkin and Cohn, 1954), was less than 0.2% (Peters, 1959).…”

Section: B Mechanismmentioning

confidence: 99%

The synthesis and secretion of albumin

Schreiber¹,

Urban

Reviews of Physiology, Biochemistry and Pharmacology

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Estimation of Nucleic Acids

Cited by 342 publications

References 64 publications

Inhibition of ribonuclease and protease activities in germinating rice seeds exposed to nickel

Inhibition of ribonuclease and protease activities in germinating rice seeds exposed to nickel

Identification of a 5'-Deoxyadenosine Deaminase in Methanocaldococcus jannaschii and Its Possible Role in Recycling the Radical S-Adenosylmethionine Enzyme Reaction Product 5'-Deoxyadenosine

The synthesis and secretion of albumin

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