Calculating Glycoprotein Similarities From Mass Spectrometric Data.
Calculating Glycoprotein Similarities From Mass Spectrometric Data.
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DOI:
10.1074/mcp.r120.002223
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发表时间:
2021
期刊:
影响因子:
--
通讯作者:
Zaia J
中科院分区:
文献类型:
--
作者:
Hackett WE;Zaia J
Complex protein glycosylation occurs through biosynthetic steps in the secretory pathway that create macro- and microheterogeneity of structure and function. Required for all life forms, glycosylation diversifies and adapts protein interactions with binding partners that underpin interactions at cell surfaces and pericellular and extracellular environments. Because these biological effects arise from heterogeneity of structure and function, it is necessary to measure their changes as part of the quest to understand nature. Quite often, however, the assumption behind proteomics that posttranslational modifications are discrete additions that can be modeled using the genome as a template does not apply to protein glycosylation. Rather, it is necessary to quantify the glycosylation distribution at each glycosite and to aggregate this information into a population of mature glycoproteins that exist in a given biological system. To date, mass spectrometric methods for assigning singly glycosylated peptides are well-established. But it is necessary to quantify glycosylation heterogeneity accurately in order to gauge the alterations that occur during biological processes. The task is to quantify the glycosylated peptide forms as accurately as possible and then apply appropriate bioinformatics algorithms to the calculation of micro- and macro-similarities. In this review, we summarize current approaches for protein quantification as they apply to this glycoprotein similarity problem. Singly glycosylated peptides can be identified unambiguously using HCD LC-MS. For calculation of glycoprotein similarity, quantify all glycopeptide glycoforms. Glycoprotein similarities can be calculated using the Tanimoto coefficient. Similarity calculations require high reproducibility of glycoproteomics LC-MS data. To understand the roles of glycoproteins in biological processes, it is necessary to quantify the changes that occur to glycosylation at individual sites and to the whole molecule. That glycoprotein glycosylation is inherently heterogeneous means that the distribution of glycoforms at each glycosite must be quantified in order to inform calculation of molecular similarities. We review analytical and statistical methods for determining glycoprotein molecular similarities from glycoproteomics data.