STRUCTURE OF THE MAJOR D1, CHAIN OF GIANT HEMOGLOBIN FROM LUMBRICUS TERRISTRIS

质谱分析的主链d1，其中之一， 蚯蚓血红蛋白中的四条血红素结合链 terrestris，揭示了测量和测量之间的差异。 序列衍生的质量表明报告序列中的错误。 本研究的目的是阐明可能的顺序 通过质谱肽图谱实验的模糊性。 后 用许多酶消化D链，蛋白水解 鉴定了51-140区域中的肽，并表明 正确的序列分配。 此外，消化 用V8蛋白酶分析显示58位的序列错误（E代替 的Q）。 N-末端Edman测序允许校正 错误鉴定的氨基酸7（G7 S）、23（Q23 E）和33（K33 R）。 的 精确序列（1-140）产生15961 Da的分子量， 比测得的质量15989 Da低28 Da。 一篇论文描述了 这些矛盾的解决办法已经公布Q.谢河，巴西-地A. 小多纳休K. Schneider，美国米尔扎岛Haller，B.T. Chait & A. F. 里格斯的巨型血红蛋白d链的结构 BBA 1337（1997）241-247。

The mass spectrometric analysis of the major chain d1, one of the four heme-binding chains in earthworm hemeglobin of Lumbricus terrestris, revealed a difference between the measured and the sequence derived masses indicating errors in the reported sequence. The purpose of this study is to clarify the possible sequence ambiguity by mass spectrometric peptide mapping experiments. After the digestion of chain d with a number of enzymes, proteolytic peptides in the region of 51-140 were identified and indicated a correct sequence assignment in this region. In addition, digestion with V8 protease revealed an sequence error in position 58 (E instead of Q). N-terminal Edman sequencing allowed the correction of misidentified amino acids 7 (G7S), 23 (Q23E) and 33 (K33R). The refined sequence (1-140) results in a molecular mass of 15961 Da which is 28 Da below the measured mass of 15989Da. A paper describing the resolution of these discrepancies has been published Q. Xie, R. A. Donahue, Jr., K. Schneider, U.A. Mirza, I. Haller, B.T. Chait & A. F. Riggs "Structure of chain d of the gigantic hemoglobin of the earthworm" BBA 1337 (1997) 241-247.