Xodo L E, Manzini G, Quadrifoglio F, van der Marel G A, van Boom J H
Nucleic Acids Res. 1986 Jul 11;14(13):5389-98. doi: 10.1093/nar/14.13.5389.
UV and CD data of the partially self-complementary heptadecadeoxynucleotide d(CGCGCGTTTTTCGCGCG), obtained as a function of temperature, salt and strand concentration, show that: at low NaCl and strand concentration the oligomer exhibits, on increasing the temperature, a biphasic thermal profile which is indicative of two structural transitions, from dimeric duplex to hairpin and from hairpin to coil; the loop stabilizes enthalpically both B and Z hairpin structures with respect to the corresponding unconstrained hexamer d(CGCGCG) by a few Kcal/mol; the oligomer undergoes a B-Z transition which appears to be complete, at 0 degree C, when induced by NaClO4; by contrast the B-Z transition induced by NaCl does not reach completeness even at salt saturation. The independence of the denaturation temperature, at high salt conditions, on the oligomer concentration indicates that the Z structure is present also in the hairpin.
作为温度、盐浓度和链浓度函数获得的部分自我互补的十七聚脱氧核苷酸d（CGCGCGTTTTTCGCGCG）的紫外和圆二色数据表明：在低NaCl和链浓度下，随着温度升高，该寡聚物呈现双相热谱，这表明存在两个结构转变，从二聚体双链体到发夹结构，再从发夹结构到线圈结构；相对于相应的无约束六聚体d（CGCGCG），环在焓上使B型和Z型发夹结构稳定了几千卡/摩尔；该寡聚物发生B-Z转变，当由高氯酸钠诱导时，在0℃时似乎是完全的；相比之下，由NaCl诱导的B-Z转变即使在盐饱和时也未达到完全。在高盐条件下，变性温度与寡聚物浓度无关，这表明Z结构也存在于发夹结构中。
