INTRACTION OF SODIUM , CALCIUM AND MAGNESIUM IONS WITH DEOXYRIBONUCLEIC ACID
INTRACTION OF SODIUM , CALCIUM AND MAGNESIUM IONS WITH DEOXYRIBONUCLEIC ACID
| dc.contributor.author | OlAYEMI, JULIUS YINKA | |
| dc.date.accessioned | 2014-02-06T15:06:49Z | |
| dc.date.available | 2014-02-06T15:06:49Z | |
| dc.date.issued | 1971-03 | |
| dc.description | Dissertation presented to The Ahmadu Bello University for the degree of DOCTOR OF PHILOSOPHY i n the Faculty of Science BY JULIUS YINKA OlAYEMI, B.Sc. Department of Chemistry Ahmadu Bello University Zaria March, 1971 | en_US |
| dc.description.abstract | The i n t e r a c t i o n of sodium ( i ) , polonium (ii) and magnesium ( I I) with Ribonucleic acid (DNA) of oaf thymus has been studied by d i a l y s i s equilibrium, conductance measurements, u l t r a v i o l et l i g h t absorption and l i g h t s c a t t e r i n g methods. The r e s u l t s have been summarized as follows: ( i ) DNA i n t e r a c t s with sodium, calcium and magnesium ions and more strongly with the two divalent c a t i o n s. ( i i ) Magnesium and calcium ions bind q u a n t i t a t i v e l y to DNA to form complexes of the following optometrists: 0.125:; 0.30:1 and 0.50:1 moles of divalent cation to one mole of nucleate phosphorus. In a l k a l i n e medium, a 1:1 mole complex was formed. ( i i i ) The s t a b i l i t y of the complexes formed between the divalent cations and DNA depends on (a) the concentration of sodium chloride supporting e l e c t r o l y t e , and ( b ) , the pH of the s o l u t i o n . The s t a ability decreases with increasing s a l t concentration and with increasing a c i d i t y f o r each DNA-M2+ system. The s t a b i l i t y constants for the DNA-Mg complexes are comparable with those of DNA-Ca2+ complexes. ( i v ) At room temperature, DNA r e t a i n s i t s n a t i v e s t r u c t u r e when prepared in s o l u t i o n of sodium chloride of at l e a s t 1 0 - 4 a n d in both caloric and magnesium chloride of about one hundredth of t h is concentration. The molar absorptivity e(P) of DNA becomes a function of the concentration of NaCl2 CaCl2 and HgClp only when the acid is denatured, but is completely independent of salt concentration when in i t s native form. DNA naturalization temperature (Tm) is increased in the presence of increasing concentrations of NaCl, CaCl2 and MgC2. Calcium and magnesium ions are more effective than the sodium ions in causing this increase in (Tm), showing a stronger interaction of the divalent orations than of the covalent sodium ions with DNA. Low concentration of calcium and magnesium ions (of the order of and below) have no destructive influence on the secondary structure of DNA. However, high concentrations of these divalent orations (of the order of 0.05H and above) have been suspected to produce a naturalization followed by a precipitation and/or aggregation of a system of DNA-M on heating beyond the naturalization temperature (Tm). (v) The method of light scattering has shown that the molecular weight of DNA depends on the concentrations of calcium and magnesium ions up to a certain maximum concentration of these orations, when the molecular weight of the DNA is doubled. This suggests that calcium and magnesium ions are engaged in an intermolecular bonding to DNA. The molecular weight of DNA was found to be independent of the concentration of sodium ions | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/543 | |
| dc.language.iso | en | en_US |
| dc.subject | INTRACTION, | en_US |
| dc.subject | SODIUM, | en_US |
| dc.subject | CALCIUM, | en_US |
| dc.subject | MAGNESIUM IONS. | en_US |
| dc.subject | DEOXYRIBONUCLEIC, | en_US |
| dc.subject | ACID | en_US |
| dc.title | INTRACTION OF SODIUM , CALCIUM AND MAGNESIUM IONS WITH DEOXYRIBONUCLEIC ACID | en_US |
| dc.type | Thesis | en_US |