PMC:7795856 / 11731-13125 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/7795856","sourcedb":"PMC","sourceid":"7795856","source_url":"https://www.ncbi.nlm.nih.gov/pmc/7795856","text":"Both PASylated peptide preparations had a purity \u003e 96% as indicated by reverse-phase chromatography (Figure 2c and Figure 3c). For Tα1-PAS, we performed a final AEX polishing step, which also allowed concentration of the peptide. At pH 10, the acetylated Tα1-PAS bound to a strong AEX resin and eluted as a homogenous peak in a salt concentration gradient. The endotoxin content of this fraction was very low, with \u003c 0.1 EU/mg, and the final yield was 15 mg acetylated Tα1-PAS per 1 L bacterial culture. In comparison, the final yield of the fully column-bound (non-acetylated) PAS-Tα1 reached 50 mg per 1 L bacterial culture after CEX chromatography and, again, the endotoxin content was below 0.1 EU/mg. Analytical size exclusion chromatography (SEC) of both PASylated peptide versions revealed a single symmetric peak without any signs of aggregation or truncation (Figure 2d and Figure 3d). The N-terminally acetylated Tα1-PAS eluted at 13.5 mL (bed volume: 24 mL), whereas PAS-Tα1 eluted at 13.2 mL, thus indicating apparent molecular sizes of 557 kDa and 665 kDa, respectively. This is more than 10 times (Tα1-PAS) or even 12 times (PAS-Tα1) larger than the true molecular mass of both PASylated peptides (52.7 kDa), which demonstrates the huge expansion of the hydrodynamic molecular volume caused by the random-coil structure of the PAS polymer, in line with previous observations [35].","tracks":[{"project":"LitCovid-PubTator","denotations":[{"id":"234","span":{"begin":582,"end":585},"obj":"Gene"},{"id":"235","span":{"begin":923,"end":926},"obj":"Gene"},{"id":"236","span":{"begin":982,"end":985},"obj":"Gene"},{"id":"237","span":{"begin":15,"end":22},"obj":"Chemical"},{"id":"238","span":{"begin":131,"end":138},"obj":"Chemical"},{"id":"239","span":{"begin":458,"end":476},"obj":"Chemical"},{"id":"240","span":{"begin":1202,"end":1210},"obj":"Chemical"},{"id":"241","span":{"begin":842,"end":853},"obj":"Disease"}],"attributes":[{"id":"A234","pred":"tao:has_database_id","subj":"234","obj":"Gene:134864"},{"id":"A235","pred":"tao:has_database_id","subj":"235","obj":"Gene:134864"},{"id":"A236","pred":"tao:has_database_id","subj":"236","obj":"Gene:134864"},{"id":"A237","pred":"tao:has_database_id","subj":"237","obj":"MESH:D010455"},{"id":"A240","pred":"tao:has_database_id","subj":"240","obj":"MESH:D010455"},{"id":"A241","pred":"tao:has_database_id","subj":"241","obj":"MESH:D001791"},{"subj":"234","pred":"source","obj":"LitCovid-PubTator"},{"subj":"235","pred":"source","obj":"LitCovid-PubTator"},{"subj":"236","pred":"source","obj":"LitCovid-PubTator"},{"subj":"237","pred":"source","obj":"LitCovid-PubTator"},{"subj":"238","pred":"source","obj":"LitCovid-PubTator"},{"subj":"239","pred":"source","obj":"LitCovid-PubTator"},{"subj":"240","pred":"source","obj":"LitCovid-PubTator"},{"subj":"241","pred":"source","obj":"LitCovid-PubTator"}],"namespaces":[{"prefix":"Tax","uri":"https://www.ncbi.nlm.nih.gov/taxonomy/"},{"prefix":"MESH","uri":"https://id.nlm.nih.gov/mesh/"},{"prefix":"Gene","uri":"https://www.ncbi.nlm.nih.gov/gene/"},{"prefix":"CVCL","uri":"https://web.expasy.org/cellosaurus/CVCL_"}]},{"project":"LitCovid-sentences","denotations":[{"id":"T70","span":{"begin":0,"end":126},"obj":"Sentence"},{"id":"T71","span":{"begin":127,"end":229},"obj":"Sentence"},{"id":"T72","span":{"begin":230,"end":356},"obj":"Sentence"},{"id":"T73","span":{"begin":357,"end":503},"obj":"Sentence"},{"id":"T74","span":{"begin":504,"end":705},"obj":"Sentence"},{"id":"T75","span":{"begin":706,"end":894},"obj":"Sentence"},{"id":"T76","span":{"begin":895,"end":961},"obj":"Sentence"},{"id":"T77","span":{"begin":962,"end":1083},"obj":"Sentence"},{"id":"T78","span":{"begin":1084,"end":1394},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"attributes":[{"subj":"T70","pred":"source","obj":"LitCovid-sentences"},{"subj":"T71","pred":"source","obj":"LitCovid-sentences"},{"subj":"T72","pred":"source","obj":"LitCovid-sentences"},{"subj":"T73","pred":"source","obj":"LitCovid-sentences"},{"subj":"T74","pred":"source","obj":"LitCovid-sentences"},{"subj":"T75","pred":"source","obj":"LitCovid-sentences"},{"subj":"T76","pred":"source","obj":"LitCovid-sentences"},{"subj":"T77","pred":"source","obj":"LitCovid-sentences"},{"subj":"T78","pred":"source","obj":"LitCovid-sentences"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"LitCovid-PubTator","color":"#c4ec93","default":true},{"id":"LitCovid-sentences","color":"#ec93de"}]}]}}