Characterization of novel oxidation products of cysteine in an active site motif peptide of PTP1B.
Characterization of novel oxidation products of cysteine in an active site motif peptide of PTP1B.
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DOI：
10.1016/j.jasms.2009.04.011
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发表时间：
2009-08
影响因子：
3.2
通讯作者：
Neubert TA
中科院分区：
文献类型：
--
作者：
Shetty V;Neubert TA
我们研究了一个合成肽HCSAGIGRS的羟基自由基（OH·）和H2O2介导的氧化产物的形成，HCSAGIGRS是蛋白酪氨酸磷酸酶1B （PTP1B）的活性位点序列基序。我们确定了在Fenton试剂（Fe+2/H2O2）和H2O2氧化反应中产生一种新型半胱氨酸亚胺HC[S(O)N]SAGIGRS。这些产物通过串联质谱实验对单电荷和双电荷前体离子进行了表征。离子捕集仪的MS3实验和四极杆飞行时间（Q-TOF）仪的LC-MS/MS实验表明，HC[S(O)N]SAGIGRS不是半胱氨酸亚磺酸[HC(SO2H)SAGIGRS]的失水产物。我们还获得了串联质谱实验的数据，为溶液中存在稳定的半胱氨酸磺酸[HC(SOH)SAGIGRS]提供了证据。根据上述实验结果，提出了半胱氨酸亚胺产物的形成机理。本研究的半胱氨酸亚胺的制备和鉴定，为进一步了解OH·和H2O2诱导蛋白酪氨酸磷酸酶氧化反应的机理提供了依据。
We investigated the formation of hydroxyl radical (OH·) and H2O2 mediated oxidation products of a synthetic peptide, HCSAGIGRS, which is an active site sequence motif of protein tyrosine phosphatase 1B (PTP1B). We determined that a novel cysteine sulfinamide HC[S(O)N]SAGIGRS is produced in the oxidation reaction by Fenton reagents (Fe+2/H2O2) as well as by H2O2. These products were characterized by tandem mass spectrometry experiments on both singly and doubly charged precursor ions. MS3 experiments using an ion trap instrument as well as LC-MS/MS experiments using a quadrupole time-of-flight (Q-TOF) instrument demonstrated that HC[S(O)N]SAGIGRS is not a water loss product of cysteine sulfinic acid [HC(SO2H)SAGIGRS]. We also obtained data from tandem mass spectrometry experiments that provided evidence for the existence of stable cysteine sulfenic acid [HC(SOH)SAGIGRS] in solution. A mechanism for the formation of the cysteine sulfinamide product is proposed based on the above experimental results. The preparation and identification of cysteine sulfinamide in this study may provide insight into the mechanism of both OH· and H2O2 induced oxidation reactions of protein tyrosine phosphatases.
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影响因子：
4.1
作者：
KOPPENOL, WH;MORENO, JJ;BECKMAN, JS
通讯作者：
BECKMAN, JS
影响因子：
4.8
作者：
Caselli, A;Marzocchini, R;Ramponi, G
通讯作者：
Ramponi, G
影响因子：
2.9
作者：
Fu, XY;Mueller, DM;Heinecke, JW
通讯作者：
Heinecke, JW
影响因子：
15
作者：
Hodges, GR;Ingold, KU
通讯作者：
Ingold, KU
影响因子：
3.9
作者：
Levine, RL;Stadtman, ER
通讯作者：
Stadtman, ER