Interactions of poly(N.epsilon.,N.epsilon.,N.epsilon.-trimethyllysine) and poly(N.delta.,N.delta.,N.delta.-trimethylornithine) with polynucleotides: salt dissociation and thermal denaturation

Granados, Edward N.; Bello, Jake

doi:10.1021/bi00555a020

Cited by 14 publications

(18 citation statements)

References 41 publications

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“…Methylation of (Lys), to [Lys(Me,)], was done with dimethyl s~1fate.I~ Before methylation, the (Lys), was dansylated with dansyl chloride to the extent of about one residue per hundred. 15 The reaction mixture was dialyzed in the cold against water, then against approximately 0.05M NaClO,, which caused precipitation, then against water (resulting in redissolution). Dansylated (Lys), was also put through a mock reaction without dimethyl sulfate and was dialyzed the same way, but no precipitation occurred.…”

Section: Methodsmentioning

confidence: 99%

Formation and stability of helical poly (N^ϵ, N^ϵ, N^ϵ‐trimethyl‐L‐lysine) in sodium perchlorate solution

Bello

1988

Biopolymers

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SynopsisPoly(trimethy1-L-lysine), [Lys(Mq)],, is converted from random coil to a-helix at about 1/30 of the NaC10, concentration required by poly(L-lysine), (Lys),. NaClO, generates turbidity in [Lys (Me),], at concentrations above that required for helix formation, and decreases turbidity above 1M NaC10,. The turbidity runs parallel to enhanced, and then decreased, fluorescence of a dansyl label. Helix formation per se does not induce enhanced fluorescence. Increasing NaC10, concentration increases T, linearly with log[NaClO,] for both (Lys), and [Lys(Mq], until the denaturing effect of high NaC10, sets in. Increasing NaClO, also increases the breadth of the transition. Heating helical [Lys(Mq)], or (Lys), does not produce a CD spectrum resembling that of "random-coil" (Lys),, except for [Lys(Mq)], at relatively low NaC10, concentration. INTRODUCTIONAn interesting fact about poly(L-lysine), (Lys),, is that perchlorates convert it from the random coil to the a-heli~.'-~ At 0.3M NaClO,, (Lys), is about 50% helical at room temperature.' Thiocyanate also promotes a-helix fonnat i~n ,~ as does trichloracetate.6 Many other anions, notably chloride, have no such effect. Poly(L-arginine) is converted to the a-helix, with 50% helicity a t about 0.05M NaC10, at room temperature: or 1/6 of that required for (Lys),. Poly(L-arginine) is also converted to the a-helix by sulfate, carbonate, and phosphate.8 Poly(L-ornithine) forms a-helix in ClO; as well but only to about 50% .9-11 Perchlorate also induces a-helix in poly(S-methylsulfonium-L-methionine), with a significant amount of helix formed at 25°C with ClO, present only as the stoichiometric counterion.12 It was reported from this laboratory earlier1'J3 that random-coil poly(N',N',N'-trimethyl-L-lysine), [Lys(Me,)],, is also converted to an ordered form, probably an a-helix, by 0.5-1M NaC10,. The interpretation of the CD spectrum, however, was not clear, as it appeared that the spectrum was distorted by the effect of turbidity. The present report describes further work on the effect of ClO, on the formation and stability of the helix in (Lys), and [Lys(Me,)],. MATERIALS AND METHODS(Lys * HBr), was obtained from Sigma. The absorption spectnln of this lot of (Lys), showed residual carbobenzyloxy blocking groups to be below 4 per 1000 lysine residues. The CD spectrum in the absence of NaC10, is in agreement with that reported by Rao and Miller', for (Lys), essentially free The reaction mixture was dialyzed in the cold against water, then against approximately 0.05M NaClO,, which caused precipitation, then against water (resulting in redissolution). Dansylated (Lys), was also put through a mock reaction without dimethyl sulfate and was dialyzed the same way, but no precipitation occurred. Both polypeptides were freeze dried. CD spectra were obtained with a Jasco 500A. Temperatures were measured with a platinum resistance element and a digital temperature indicator (Omega Model 199P2), and were constant to 0.2"C a t the highest temperature. Temperature was controlled by a circ...

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Section: Methodsmentioning

confidence: 99%

Formation and stability of helical poly (N^ϵ, N^ϵ, N^ϵ‐trimethyl‐L‐lysine) in sodium perchlorate solution

Bello

1988

Biopolymers

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“…in which trimethylammonium is the cationic head [8] and by a series of cationic molecules, such as polylysine [9, 101, distamycin, and netropsin [ll], and a wide class of nonintercalative bis-guanylhydrazones [ 121, bisamidines, and bis-quarternary ammonium heterocycles [ 131.…”

Section: L-l Y S -N ( M~)~] mentioning

confidence: 99%

Theoretical study of the interaction of tetramethylammonium with double‐stranded oligonucleotides

Gresh¹,

Pullman²

1983

Int J of Quantum Chemistry

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Computations are performed on the interaction specificities of tetramethylammonium (TMA) for double-stranded oligonucleotides held in the B conformation. The effects of base sequence and chain length are investigated. In the short oligomers (helices formed from dinucleoside monophosphates and trinucleoside diphosphates), the interaction energies of TMA are larger in the major groove of (dG),, . (dC), than in the minor groove of either (dA), . (dT), or ( d A d T ) , . Upon lengthening the oligomers, and owing to the gradual shaping of the grooves of the helix and cumulative effect of the phosphates, TMA is shown to increasingly favor the minor groove of (dA), . (dT), with respect to the major groove of (dG), . (dC),, with a sizeable energy difference computed at the pentanucleoside hexaphosphate level. The binding of TMA in the minor groove of (dA), (dT). involves stabilizing contacts with several sites, on the bases and on the deoxyriboses. Configurations locating the cation closer to the thymine strand are slightly preferred over configurations locating it closer to the adenine strand.

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“…shown to prevent varicella infection in leukemic children who had been exposed to infection' 5 . IFN has been shown to circulate in some parasitic infections 1 6 and may be an aspect of the natural…”

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confidence: 99%

Interferon Inducers against Infectious Diseases

Bello¹,

O’Malley²

1990

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Interactions of poly(N.epsilon.,N.epsilon.,N.epsilon.-trimethyllysine) and poly(N.delta.,N.delta.,N.delta.-trimethylornithine) with polynucleotides: salt dissociation and thermal denaturation

Cited by 14 publications

References 41 publications

Formation and stability of helical poly (N^ϵ, N^ϵ, N^ϵ‐trimethyl‐L‐lysine) in sodium perchlorate solution

Formation and stability of helical poly (N^ϵ, N^ϵ, N^ϵ‐trimethyl‐L‐lysine) in sodium perchlorate solution

Theoretical study of the interaction of tetramethylammonium with double‐stranded oligonucleotides

Interferon Inducers against Infectious Diseases

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Interactions of poly(N.epsilon.,N.epsilon.,N.epsilon.-trimethyllysine) and poly(N.delta.,N.delta.,N.delta.-trimethylornithine) with polynucleotides: salt dissociation and thermal denaturation

Cited by 14 publications

References 41 publications

Formation and stability of helical poly (Nϵ, Nϵ, Nϵ‐trimethyl‐L‐lysine) in sodium perchlorate solution

Formation and stability of helical poly (Nϵ, Nϵ, Nϵ‐trimethyl‐L‐lysine) in sodium perchlorate solution

Theoretical study of the interaction of tetramethylammonium with double‐stranded oligonucleotides

Interferon Inducers against Infectious Diseases

Contact Info

Product

Resources

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Formation and stability of helical poly (N^ϵ, N^ϵ, N^ϵ‐trimethyl‐L‐lysine) in sodium perchlorate solution

Formation and stability of helical poly (N^ϵ, N^ϵ, N^ϵ‐trimethyl‐L‐lysine) in sodium perchlorate solution