Matsubayashi Y, Hanai H, Hara O, Sakagami Y
Department of Applied Biological Sciences, Nagoya University Chikusa, Japan.
Biochem Biophys Res Commun. 1996 Aug 5;225(1):209-14. doi: 10.1006/bbrc.1996.1155.
Sulfated pentapeptide phytosulfokine-alpha (PSK-alpha) is the first chemically characterized peptidal plant growth factor that induces proliferation of the mesophyll cells of asparagus. To determine the active core involved in the sequence PSK-alpha, we synthesized PSK-alpha and twelve PSK-alpha analogs by the solid phase peptide synthesis and the direct sulfation to the peptide-resin using dimethylformamide-sulfurtrioxide (DMF-SO3) complex. The truncated analogs of PSK-alpha without the first and second C-terminal amino acids retained 8% and 20% of the activity of the parent pentapeptide, respectively. Deletion of the sulfate groups of Tyr1 and Tyr3 resulted in compounds with 0.6% and 4% of the activity of PSK-alpha, indicating that the sulfate group of Tyr1 is more important than that of Tyr3 for the expression of its activity. In contrast, the N-terminal truncated analog and unsulfated analog exhibited little or no activity. Thus the N-terminal tripeptide fragment H-Tyr(SO3H)-Ile-Tyr(SO3H)-OH has been identified as the active core of PSK-alpha.
硫酸化五肽植物硫肽素-α（PSK-α）是首个经化学表征的肽类植物生长因子，可诱导芦笋叶肉细胞增殖。为确定PSK-α序列中起作用的活性核心，我们通过固相肽合成法以及使用二甲基甲酰胺-三氧化硫（DMF-SO₃）络合物对肽树脂进行直接硫酸化，合成了PSK-α和12种PSK-α类似物。缺失C末端第一和第二个氨基酸的PSK-α截短类似物分别保留了母体五肽8%和20%的活性。Tyr1和Tyr3硫酸基团的缺失导致化合物活性仅为PSK-α的0.6%和4%，这表明Tyr1的硫酸基团对其活性表达比Tyr3的更重要。相比之下，N末端截短类似物和未硫酸化类似物几乎没有活性。因此，N末端三肽片段H-Tyr(SO₃H)-Ile-Tyr(SO₃H)-OH已被确定为PSK-α的活性核心。
