Krishnamurthy T, Szafraniec L, Hunt D F, Shabanowitz J, Yates J R, Hauer C R, Carmichael W W, Skulberg O, Codd G A, Missler S
U.S. Army Chemical Research, Development, and Engineering Center, Aberdeen Proving Ground, MD 21010-5423.
Proc Natl Acad Sci U S A. 1989 Feb;86(3):770-4. doi: 10.1073/pnas.86.3.770.
Combined use of chemical degradation, derivatization, and tandem mass spectrometry for rapid structural characterization of toxic cyclic peptides from blue-green algae at the nanomole level is described. Previously, all blue-green algal toxins were thought to belong to a family of seven-residue cyclic peptides, having the general structure cyclo-D-Ala-L-Xaa-erythro-beta-methyl-D-isoaspartic acid-L-Yaa-Adda-D-isoglutamic acid-N-methyldehydroalanine, where Xaa and Yaa represent variable amino acids of the L configuration and Adda is 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-deca-4,6-dienoic acid. Structural characterization of two additional toxins indicates that further variability can exist within this family of naturally occurring toxic cyclic peptides. Isoaspartic acid and dehydroalanine can substitute for beta-methylisoaspartic acid and N-methyldehydroalanine, respectively.
本文描述了结合化学降解、衍生化和串联质谱法，用于在纳摩尔水平上快速对蓝藻中有毒环肽进行结构表征。以前，所有蓝藻毒素都被认为属于一个七残基环肽家族，其一般结构为环-D-丙氨酸-L-Xaa-赤藓糖-β-甲基-D-异天冬氨酸-L-Yaa-Adda-D-异谷氨酸-N-甲基脱氢丙氨酸，其中Xaa和Yaa代表L构型的可变氨基酸，Adda为3-氨基-9-甲氧基-2,6,8-三甲基-10-苯基-癸-4,6-二烯酸。另外两种毒素的结构表征表明，在这个天然存在的有毒环肽家族中可能存在进一步的变异性。异天冬氨酸和脱氢丙氨酸可分别替代β-甲基异天冬氨酸和N-甲基脱氢丙氨酸。
