Studies on ribonuclease in tobacco leaves I. Purification and properties

Frisch-Niggemeyer, W; Reddi, K. K.

doi:10.1016/0006-3002(57)90051-3

Cited by 120 publications

(11 citation statements)

References 6 publications

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“…HCl salts of the dibasic amino acids, diamines, and polyamines were obtained from Sigma Chemical Co. Yeast RNA, also obtained from Sigma, was purified by the method of FrischNiggemeyer and Reddi (8). Cellulysin B was obtained from Calbiochem.…”

Section: Methodsmentioning

confidence: 99%

Dual Mechanisms in Polyamine-mediated Control of Ribonuclease Activity in Oat Leaf Protoplasts

Kaur‐Sawhney¹,

Altman²,

Galston³

1978

Plant Physiol.

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Dibasic amino acids and polyamies added to oat ( Avea sadvaL.) leaf protoplast isolation media decrease the RNase activity of extracted protoplasts relative to controls. This effect, wich is manifested even when the added polyamine Is removed by exhaustive dialysis prior to assay, is due to a prevention of the rise in RNase activity which usually folows protoplast Isolation. Polyanines, but not dibasic amino acids, also decrease RNase activity in diro. This hI vitro effect seems to result from electrovalent attachment of the polyamine to the RNA, because the greater the net positive charge on the polyane, the greater is its inhibitory effect ih ntro. The activity of dibasic amo acids when added during protoplast isolation probably results from their conversion to polyamines.In previous investigations (1, 9, 1 1), we reported that the RNase activity of oat leaf protoplasts increases sharply during the several hr of their incubation. This rise in RNase is accompanied by decreased net incorporation of uridine into RNA, as well as by general deterioration and ultimate lysis of the protoplasts. We suggested that this increased RNase activity in protoplasts and leaves (24, 25) may be in part responsible for the limited survival and only rare cell division activity of cereal protoplasts in culture (5,19).The rise in RNase activity is drastically inhibited if protoplasts are incubated in the presence of L-arginine or if they are isolated from leaves pretreated with L-arginine, L-lysine, cadaverine, putrescine, cycloheximide, or kinetin (1,11,13). Protoplasts so treated are more stable to lysis and show higher RNA-synthetic activity (1, 11, 13, 14) than controls. It appeared that an understanding of the mechanism by which polyamines inhibit the rise in RNase activity might help in obtaining more stable protoplasts which could be useful in cell culture experiments aimed at improving cereal crops.Although polyamines are known to affect the synthesis of DNA, RNA, and protein (2,4,6, 20), there are only a few reports, limited to bacterial and mammalian systems, dealing with the effect of polyamines on DNA and RNA degradation by nucleases (3,17, 23 Preparation of Protoplasts. Procedures for growth of plants and isolation of protoplasts have been described earlier (9). Briefly, for studies of RNase in protoplasts (in vivo), the lower epidermis of 6-day-old leaves of Avena sativa L. (var. Victory) was peeled off and the peeled leaves floated on a solution containing 0.5% (w/v) Cellulysin in 0.6 M mannitol and I mm phosphate buffer at pH 5.7, and incubated for 2 hr at 31 ± 1 C to extract protoplasts. Similar protoplast isolations were carried out in the presence of 10 mM L-arginine or 1 mm spermine. The released protoplasts were collected by centrifugation at 50g for 8 min, washed twice with 0.6 M mannitol (pH 5.7), resuspended in mannitol, counted in a hemocytometer, and adjusted to 1 x 106 protoplasts/ml. Oneml aliquots of suspension were used for determining RNase activity in the protoplasts.For studies of RNase in c...

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Section: Methodsmentioning

confidence: 99%

Dual Mechanisms in Polyamine-mediated Control of Ribonuclease Activity in Oat Leaf Protoplasts

Kaur‐Sawhney¹,

Altman²,

Galston³

1978

Plant Physiol.

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“…But whereas the latter hydrolyses the purine 2':3'-cyclic phosphates to the 3'-phosphates, the V-route ribonuclease appears to hydrolyse all the cyclic phosphates in this way. It also differs in having optimum activity at pH 7 instead of pH 5 (Holden & Pirie, 1955;Frisch-Niggemeyer & Reddi, 1957), resembling more closely pancreatic ribonuclease in this respect (Kunitz, 1940;Holden & Pirie, 1955). The influence of magnesium upon ribonuclease is difficult to assess.…”

Section: Resultsmentioning

confidence: 99%

“…The influence of magnesium upon ribonuclease is difficult to assess. It has been shown to activate pancreatic ribonuclease (Ceriotti, 1949) and leaf ribonuclease (Holden & Pirie, 1955) and also partially to inhibit these enzymes under other circumstances (Mallette & Lamanna, 1954;Holden & Pirie, 1955;Frisch-Niggemeyer & Reddi, 1957). Although the inclusion of a chelating agent is necessary for the exclusive formation of cyclic nucleotides by the V route it does not necessarily follow that the V-route ribonuclease is inhibited by magnesium.…”

Section: Resultsmentioning

confidence: 99%

The autodegradation of ribonucleoprotein in Escherichia coli

1961

Biochemical Journal

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“…Ribonucleic acid (Na salt from yeast) obtained from L. Light and Co. Ltd. (Colnbrook, Bucks,) was purified according to Frisch-Niggemeyer & Reddi (1957). The purified material was dialysed, with constant stirring, for 24 hr under repeated changes of de-ionized water.…”

Section: Introductionmentioning

confidence: 99%

Nucleases of Mycoplasma

Razin

Knyszynski

LifsuLtz

1964

Journal of General Microbiology

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SUMMARYNuclease activity was observed in several saprophytic and parasitic Mycoplasma organisms ; the nucleases of Mycoplasma laidlawii were studied in detail. Nuclease activity of this organism was highest a t the early logarithmic phase of growth, and was found mainly in the soluble fraction of the organisms. Anion-exchange chromatography of the proteins of the soluble fraction separated ribonuclease from deoxyribonuclease activity. Each enzyme had an alkaline pH optimum, required magnesium ions for activity, and degraded native and heat-denatured nucleic acids. M . laidlazvii RNase degraded RNA-core. RNA inhibited the degradation of DNA by M . laidlawii deoxyribonuclease. The implications of these findings with respect to the effects of RNA and DNA on growth of M . laidlazvii are discussed.

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Studies on ribonuclease in tobacco leaves I. Purification and properties

Cited by 120 publications

References 6 publications

Dual Mechanisms in Polyamine-mediated Control of Ribonuclease Activity in Oat Leaf Protoplasts

Dual Mechanisms in Polyamine-mediated Control of Ribonuclease Activity in Oat Leaf Protoplasts

The autodegradation of ribonucleoprotein in Escherichia coli

Nucleases of Mycoplasma

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