Secondary structure of protamine in sperm nuclei: an infrared spectroscopy study

BMC Structural Biology

Table 1 Percentages of secondary structure of salmon and squid protamines in sperm nuclei.

	Salmon protamine		Squid protamine
Assignment	140 mM		140 mM		600 mM
	Band cm ^-1	%	Band cm ^-1	%	Band cm ^-1	%
Turns	1674	16	1669	17	1669	17
Turns	1663	22	1662	20	1661	22
α-helix	1652	20	1650	40	1650	39
Random coil/flexible regions	1642	42	1640	23	1640	22
Side Chain	1609	-	1609	-	1609	-

The concentration of nuclei expressed as DNA concentration was 5 mg/ml. Band position (cm^-1) and percentage area (%) and assignment of the components were obtained after curve fitting of the amide I band (D₂O). The buffer was 10 mM Hepes plus 140 or 600 mM NaCl, pH7.0. The values were rounded off to the nearest integer.

ISSN: 1472-6807