Warning: Constant ABSPATH already defined in D:\www\www164\blog\wp-config.php on line 31 {"id":536,"date":"2021-07-08T13:01:27","date_gmt":"2021-07-08T11:01:27","guid":{"rendered":"https:\/\/www.protpi.ch\/blog\/?p=536"},"modified":"2021-07-08T13:02:07","modified_gmt":"2021-07-08T11:02:07","slug":"c-mannosylation","status":"publish","type":"post","link":"https:\/\/www.protpi.ch\/blog\/bioinformatics\/2021\/07\/c-mannosylation\/","title":{"rendered":"C-Mannosylation"},"content":{"rendered":"\n

Overview<\/h2>\n\n\n\n

C<\/em>-Mannosylation is a unique type of protein glycosylation. A C-C bond is formed between the C1 atom of an \u03b1-mannose and the C2 atom of the indole ring of a tryptophan residue via mannosyl-transferases.<\/p>\n\n\n\n

pKa<\/td>NC<\/td>Loss<\/td>Gain<\/td>Deltamass<\/td>H<\/td>AA<\/td>UV-Spec<\/td>Pattern<\/td><\/tr>
–<\/td>No<\/td>H<\/td>C6<\/sub>H11<\/sub>O5<\/sub><\/td>Av: 162.1408
M: 162.0528<\/td>		0<\/td>W<\/td>–<\/td>W(?=..W)<\/td><\/tr><\/tbody><\/table>
Physicochemical properties of C<\/em>-mannosylation that are stored in the modification database of Prot pi (NC: Native charge; H: Relative hydrophobicity; AA: Modified amino acid; Pattern: Regex for sequence-motif recognition).<\/figcaption><\/figure>\n\n\n\n

In-depth mechanism<\/h2>\n\n\n\n

Glycosylations of proteins are one of the most common and widespread post-translational modifications. Best known are N<\/em>– and O<\/em>-glycosylations. More than 25 years ago, a new type of glycosylation, C<\/em>-mannosylation, was discovered. C<\/em>-Mannosylation differs fundamentally from previously described types of glycosylation. A C-C bond is formed between the C1 atom of an \u03b1-mannose and the C2 atom of the indole ring of a tryptophan residue. The reaction is catalysed by mannosyltransferases, which use dolychyl-phosphate-mannose as donor for the mannose moiety\u200b1,2\u200b<\/sup><\/span>. Dolychyl-phosphate-mannose is formed from GDP-mannose and dolichol-phosphate on the cytosolic side of the endoplasmatic reticulum\u200b3\u200b<\/sup><\/span>. The mechanism of C<\/em>-mannosylation is shownin figure 1.<\/p>\n\n\n\n

\"\"
Figure 1: Mechanism of C<\/em>-mannosylation. A mannose moiety is transferred from dolychyl-phosphate-mannose to the first tryptophan of a W-X-X-W motif via mannosyltransferases. A C-C bond is formed between the C1 atom of an \u03b1-mannose and the C2 atom of the indole ring of the tryptophan residue.<\/figcaption><\/figure>\n\n\n\n

Mannosyltransferases recognize W-X-X-W motifs and C<\/em>-mannosylate the first tryptophan in the sequence. However, this pattern can vary slightly from organism to organism\u200b2\u200b<\/sup><\/span>. The exchange of the second tryptophan residue for other amino acids strongly restricts or even completely prevents C<\/em>-mannosylation. The influence of the two amino acids between the tryptophan residues is still the subject of current studies\u200b1\u200b<\/sup><\/span>. The W-X-X-W motif occurs in many proteins, which suggests that C<\/em>-mannosylation is a common an widespread post-translational modification. The function of C<\/em>-mannosylation is still largely unknown today\u200b1,2\u200b<\/sup><\/span>. The hydrophobicity of a protein is not altered by C<\/em>-mannosylation.<\/p>\n\n\n\n

References<\/h3>
  1. \n
    1. <\/div>
    Furmanek A, Hofsteenge J. Protein C-mannosylation: facts and questions. Acta biochimica Polonica<\/i>. 2000;47:781\u2013789.<\/div>\n <\/div>\n<\/li>
  2. \n
    2. <\/div>
    Lafite P, Daniellou R. Rare and unusual glycosylation of peptides and proteins. Natural Product Reports<\/i>. 2012;29:729\u2013738. doi:10.1039\/C2NP20030A<\/a><\/div>\n <\/div>\n<\/li>
  3. \n
    3. <\/div>
    Maeda Y, Kinoshita T. Dolichol-phosphate mannose synthase: structure, function and regulation. Biochimica et biophysica acta<\/i>. 2008;1780:861\u2013868. doi:10.1016\/j.bbagen.2008.03.005<\/a><\/div>\n <\/div>\n<\/li><\/ol><\/section>\n","protected":false},"excerpt":{"rendered":"

    Overview C-Mannosylation is a unique type of protein glycosylation. A C-C bond is formed between the C1 atom of an \u03b1-mannose and the C2 atom of the indole ring of a tryptophan residue via mannosyl-transferases. pKa NC Loss Gain Deltamass H AA UV-Spec Pattern – No H C6H11O5 Av: 162.1408M: 162.0528 0 W – W(?=..W) […]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-536","post","type-post","status-publish","format-standard","hentry","category-bioinformatics"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/posts\/536","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/comments?post=536"}],"version-history":[{"count":2,"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/posts\/536\/revisions"}],"predecessor-version":[{"id":540,"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/posts\/536\/revisions\/540"}],"wp:attachment":[{"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/media?parent=536"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/categories?post=536"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.protpi.ch\/blog\/wp-json\/wp\/v2\/tags?post=536"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}