Structure and function of protamines: an 1H nuclear magnetic resonance investigation of the interaction of clupeines with mononucleotides

A thermodynamic study of herring protamine–DNA complex by differential scanning calorimetry

“…The clupeine sulfate was a Sigma product (Grade III-cell extracted material, histone-free) and it was used without further purification. Since it has already been observed that there was no meaningful difference in the binding and thermal stability of hs-DNA in the presence of each clupeine fraction, 7,17 the natural mixture of the three fractions was directly used for our measurements. The protamine solution was prepared by dissolving the sulfate salt in the same buffer solution as DNA and exhaustively dialysed against it.…”

“…[3][4][5][6] More recently, NMR data have shown that the three clupeine fractions seem to possess the same affinity and binding modes for purinic and pyrimidinic mononucleotides. 7 The lack of a unique view regarding the DNA=protamine system could be partly due to their strong binding affinity, commonly manifested by polycationic substances for negatively charged polynucleotides, and extremely difficult to characterise experimentally. Standard techniques (that rely on the direct determination of the concentration of the molecules at equilibrium) fail, as the detection is compromised by the low concentration of unbound species in solution.…”

Are there molecules of nucleoprotamine?

“…However, they acquire somewhat more compact conformation in solution upon addition of 0.5 M phosphate, (43) 0.1 M TRIS, (17) 0.3 M NaCl, (44) or millimolar amounts of nucleotides. (45) Fractions YI and Z of clupeine exhibit reduced mobility in some sections of their molecules in the presence of a large excess of phosphate ions. (46) Based on the viscosity data, the largest changes could be attributed to the YI fraction of clupeine.…”

6. Administration of Centella Leaf Extract (Centella asiatica (L.) Urban) for Decreasing cAMP Responsive Element Modulator (CREM) Expression in Testicular Seminiferous Tubule of Male Rats (Rattus norvegicus)

“…CREM transcription factor can regulate the expression of some post meiosis genes, such as transition protein and protamine (Sassone-Corsi, 1998). Protamine is a major protein on spermatozoa that has a low molecular weight which is responsible for protecting deoxyribonucleic acid (DNA) in spermatid cells (D'Auria et al, 1993).…”