Pearlstone J R, Carpenter M R, Johnson P, Smillie L B
Proc Natl Acad Sci U S A. 1976 Jun;73(6):1902-6. doi: 10.1073/pnas.73.6.1902.
The complete amino-acid sequence of rabbit skeletal troponin-T is reported. The protein consists of a single polypeptide chain of 259 amino acids; it has an acetylated amino terminus and a molecular weight of 30,503. The sequence was determined by manual and/or automated Edman degradation techniques on the six fragments obtained after cleavage with cyanogen bromide. The larger fragments were further digested with trypsin, chymotrypsin, alpha-lytic protease, thermolysin, or pepsin to obtain smaller fragments suitable for manual sequencing. About 50% of the residues are charged at neutral pH with highly acidic amino-terminal (residues 1-39) and highly basic carboxyl-terminal regions (residues 221-259). Predictions of secondary structure indicate 37% helical content with two long sections (residues 80-102 and 122-146) in that portion of the molecule implicated in binding to tropomyocin. Two of the three phosphorylated sites in the molecule are located at serine-1 and serine-149 or -150. The sequence about the latter site resembles somewhat the phosphorylase kinase phosphorylation sites in phosphorylase alpha and troponin-I.
本文报道了兔骨骼肌肌钙蛋白-T的完整氨基酸序列。该蛋白质由一条含259个氨基酸的单多肽链组成；其氨基末端为乙酰化形式，分子量为30,503。通过对溴化氰裂解后得到的六个片段采用手动和/或自动的埃德曼降解技术来确定序列。较大的片段再用胰蛋白酶、胰凝乳蛋白酶、α-裂解蛋白酶、嗜热菌蛋白酶或胃蛋白酶进一步消化，以获得适合手动测序的较小片段。在中性pH条件下，约50%的残基带有电荷，氨基末端（第1 - 39位残基）高度酸性，羧基末端区域（第221 - 259位残基）高度碱性。二级结构预测表明，该分子中参与与原肌球蛋白结合的部分有37%的螺旋含量，包含两个长片段（第80 - 102位残基和第122 - 146位残基）。该分子中三个磷酸化位点中的两个位于丝氨酸-1以及丝氨酸-149或-150处。后一个位点附近的序列与磷酸化酶α和肌钙蛋白-I中的磷酸化酶激酶磷酸化位点有些相似。
