Zhigang A, Löw R, Rausch T, Lüttge U, Ratajczak R
Institut für Botanik, Technische Hoschschule Darmstadt, Darmstadt, Germany.
FEBS Lett. 1996 Jul 8;389(3):314-8. doi: 10.1016/0014-5793(96)00556-x.
In the facultative halophyte Mesembryanthemum crystallinum, the salt- or age-induced transition to crassulacean acid metabolism (CAM) leads to the occurrence of a tonoplast-bound 32 kDa polypeptide (Di). The alignment of its N-terminal protein sequence with protein sequences of recently cloned higher plant V-ATPase B-subunits indicates that Di may be derived from subunit B by proteolytic removal of a protein fragment of about 20 kDa from its N-terminus. Furthermore, an antiserum directed against Di cross-reacts with subunit B from Nicotiana tabacum. It inhibits both proton pumping and ATP hydrolysis of the holoenzyme in M. crystallinum. As Di remains firmly attached to the holoenzyme the proteolytic processing may have functional implications.
在兼性盐生植物冰叶日中花中，盐胁迫或衰老诱导的向景天酸代谢（CAM）的转变导致一种液泡膜结合的32 kDa多肽（Di）的出现。其N端蛋白质序列与最近克隆的高等植物V-ATPase B亚基的蛋白质序列比对表明，Di可能是由亚基B通过从其N端蛋白水解去除约20 kDa的蛋白质片段而产生的。此外，一种针对Di的抗血清与烟草的亚基B发生交叉反应。它抑制了冰叶日中花全酶的质子泵浦和ATP水解。由于Di仍牢固地附着在全酶上，这种蛋白水解加工可能具有功能意义。
