{"id":1069,"date":"2016-08-08T16:35:21","date_gmt":"2016-08-08T20:35:21","guid":{"rendered":"https:\/\/www.bumc.bu.edu\/ftms\/?page_id=1069"},"modified":"2016-08-17T15:51:19","modified_gmt":"2016-08-17T19:51:19","slug":"acylproteome","status":"publish","type":"page","link":"https:\/\/www.bumc.bu.edu\/ftms\/research\/acylproteome\/","title":{"rendered":"Acylproteome"},"content":{"rendered":"<p>Protein <em>S<\/em>-palmitoylation results\u00a0from the covalent attachment of a palmitate\u00a0to the cysteine sulfhydryl group via a labile thioester linkage. <em>S<\/em>-palmitoylation is reversible and dynamic, and plays an important regulatory role in protein trafficking, membrane localization, and cellular signaling.\u00a0<em>S<\/em>-palmitoylation is\u00a0traditionally detected by radioisotope labeling, but the procedure is toxic, time consuming, and generally cannot specify the palmitoylation sites. An alternative approach utilizing metabolic labeling and click chemistry has shown great promise in large-scale profiling of protein palmitoylation using cell lines, but cannot be easily extended to study palmitoylation in large organisms. Indirect detection\u00a0methods utilizing\u00a0the acyl-biotinyl exchange chemistry have also been\u00a0applied to study\u00a0<em>S<\/em>-palmitoylation, but false discovery of palmitoylation may arise due to incomplete blockage of free cysteine thiol(s) and\/or the presence of other types of acylation. Meanwhile, direct detection and quantification of\u00a0<em>S<\/em>-palmitoylation by mass spectrometry is challenging because of the tendency of palmitoyl loss during sample preparation and tandem MS analysis.<\/p>\n<p>We have recently developed a sample preparation protocol that preserves\u00a0<em>S<\/em>-palmitoylation for on-line LC-MS\/MS analysis and a derivatization strategy that\u00a0allows relative quantification of protein palmitoylation. We showed that our approach has sensitivity comparable to the traditional radioactive labeling method, and does not suffer from\u00a0some of the limitations that are inherent to metabolic labeling approaches. We discovered that during proteomic sample preparation, the <em>S<\/em>-palmitoyl group may migrate to an amino group at\u00a0the protein N-terminus or on the lysine side chain, potentially leading to false discovery of <em>N<\/em>-palmitoylation.\u00a0We showed that addition of detergent stabilizes\u00a0<em>S<\/em>-palmitoylation, thus preventing\u00a0inter-molecular\u00a0<em>S<\/em>&#8211; to\u00a0<em>N<\/em>-palmitoyl transfer and based-catalyzed palmitoyl loss. However, the choice of detergent is crucial as the use\u00a0of certain MS-compatible acid-labile surfactant can lead to\u00a0artifactual modifications of the cysteine thiol that could be misinterpreted as palmitoylation or\u00a0other lipid modifications.<\/p>\n<p>Our current effort is focused on the development of palmitoyl peptide enrichment methods. We will also explore the potential of direct palmitoyl analysis by MS in biological systems.<\/p>\n<p>The following papers describe\u00a0this work in detail:<\/p>\n<ul>\n<li>Ji, Y.; Bachschmid, M. M.; Costello, C. E.; Lin, C. <em>S<\/em>&#8211; to N-Palmitoyl Transfer during Proteomic Sample Preparation\u00a0<em>J. Am. Soc. Mass Spectrom.<\/em> <strong>2016<\/strong>, <em>27(4)<\/em>, 677-685.<img loading=\"lazy\" src=\"\/ftms\/files\/2016\/08\/graphic-abstract-small-260x300.png\" alt=\"graphic abstract small\" width=\"260\" height=\"300\" class=\"alignnone size-medium wp-image-1091\" srcset=\"https:\/\/www.bumc.bu.edu\/ftms\/files\/2016\/08\/graphic-abstract-small-260x300.png 260w, https:\/\/www.bumc.bu.edu\/ftms\/files\/2016\/08\/graphic-abstract-small.png 300w\" sizes=\"(max-width: 260px) 100vw, 260px\" \/><\/li>\n<li><span>Ji, Y.; Liu, M.; Bachschmid, M. M.; Costello, C. E.; Lin, C.\u00a0Surfactant-Induced Artifacts during Proteomic Sample Preparation\u00a0<em>Anal. Chem.<\/em> <strong>2015<\/strong>, <em>87 (11)<\/em>, 5500-5504.<img loading=\"lazy\" src=\"\/ftms\/files\/2016\/08\/TOC-Figure1.png\" alt=\"TOC Figure\" width=\"500\" height=\"167\" class=\"alignnone size-full wp-image-1089\" \/><\/span><\/li>\n<li><span>Ji, Y.; Leymarie, N.; Haeussler, D. J.; Bachschmid, M. M.; Costello, C. E.; Lin, C.\u00a0Direct Detection of <em>S<\/em>-Palmitoylation by Mass Spectrometry\u00a0<em>Anal. Chem.<\/em> <strong>2013<\/strong>, <em>85 (24)<\/em>, 11952-11959.<img loading=\"lazy\" src=\"\/ftms\/files\/2016\/08\/TOC-Figure.png\" alt=\"TOC Figure\" width=\"500\" height=\"164\" class=\"alignnone size-full wp-image-1082\" \/><\/span><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Protein S-palmitoylation results\u00a0from the covalent attachment of a palmitate\u00a0to the cysteine sulfhydryl group via a labile thioester linkage. S-palmitoylation is reversible and dynamic, and plays an important regulatory role in protein trafficking, membrane localization, and cellular signaling.\u00a0S-palmitoylation is\u00a0traditionally detected by radioisotope labeling, but the procedure is toxic, time consuming, and generally cannot specify the palmitoylation [&hellip;]<\/p>\n","protected":false},"author":1267,"featured_media":0,"parent":41,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/pages\/1069"}],"collection":[{"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/users\/1267"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/comments?post=1069"}],"version-history":[{"count":10,"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/pages\/1069\/revisions"}],"predecessor-version":[{"id":1092,"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/pages\/1069\/revisions\/1092"}],"up":[{"embeddable":true,"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/pages\/41"}],"wp:attachment":[{"href":"https:\/\/www.bumc.bu.edu\/ftms\/wp-json\/wp\/v2\/media?parent=1069"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}