Dataset Information

Investigating the dynamics and polyanion binding sites of fibroblast growth factor-1 using hydrogen-deuterium exchange mass spectrometry.

ABSTRACT: In this study, we examined the local dynamics of acidic fibroblast growth factor (FGF-1) as well as the binding sites of various polyanions including poly-sulfates (heparin and low MW heparin) and poly-phosphates (phytic acid and ATP) using hydrogen-deuterium exchange mass spectrometry (HX-MS). For local dynamics, results are analyzed at the peptide level as well as in terms of buried amides employing crystallographic B-factors and compared with a residue level heat map generated from HX-MS results. Results show that strand 4 and 5 and the turn between them to be the most flexible regions as was previously seen by NMR. On the other hand, the C-terminal strands 8, 9, and 10 appear to be more rigid which is also consistent with crystallographic B-factors as well as local dynamics studies conducted by NMR. Crystal structures of FGF-1 in complex with heparin have shown that heparin binds to N-terminal Asn18 and to C-terminal Lys105, Tryp107, Lys112, Lys113, Arg119, Pro121, Arg122, Gln127, and Lys128 indicating electrostatic forces as dominant interactions. Heparin binding as determined by HX-MS is consistent with crystallography data. Previous studies have also shown that other polyanions including low MW heparin, phytic acid and ATP dramatically increase the thermal stability of FGF-1. Using HX-MS, we find other poly anions tested bind in a similar manner to heparin, primarily targeting the turns in the lysine rich C-terminal region of FGF-1 along with two distinct N-terminal regions that contains lysines and arginines/histidines. This confirms the interactions between FGF-1 and polyanions are primary directed by electrostatics.

SUBMITTER: Angalakurthi SK

PROVIDER: S-EPMC5980514 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Investigating the dynamics and polyanion binding sites of fibroblast growth factor-1 using hydrogen-deuterium exchange mass spectrometry.

Angalakurthi Siva K SK Tenorio Connie A CA Blaber Michael M Middaugh Charles Russell CR

Protein science : a publication of the Protein Society 20180503 6

In this study, we examined the local dynamics of acidic fibroblast growth factor (FGF-1) as well as the binding sites of various polyanions including poly-sulfates (heparin and low MW heparin) and poly-phosphates (phytic acid and ATP) using hydrogen-deuterium exchange mass spectrometry (HX-MS). For local dynamics, results are analyzed at the peptide level as well as in terms of buried amides employing crystallographic B-factors and compared with a residue level heat map generated from HX-MS resu ...[more]

PMID: 29645318

Similar Datasets

Project description:Laforin and starch excess 4 (SEX4) are founding members of a class of phosphatases that dephosphorylate phosphoglucans. Each protein contains a carbohydrate binding module (CBM) and a dual-specificity phosphatase (DSP) domain. The gene encoding laforin is mutated in a fatal neurodegenerative disease called Lafora disease (LD). In the absence of laforin function, insoluble glucans that are hyperphosphorylated and exhibit sparse branching accumulate. It is hypothesized that these accumulations trigger the neurodegeneration and premature death of LD patients. We recently demonstrated that laforin removes phosphate from phosphoglucans and hypothesized that this function inhibits insoluble glucan accumulation. Loss of SEX4 function in plants yields a similar cellular phenotype; an excess amount of insoluble, hyperphosphorylated glucans accumulates in cells. While multiple groups have shown that these phosphatases dephosphorylate phosphoglucans, there is no structure of a glucan phosphatase and little is known about the mechanism whereby they perform this action. We utilized hydrogen-deuterium exchange mass spectrometry (DXMS) and structural modeling to probe the conformational and structural dynamics of the glucan phosphatase SEX4. We found that the enzyme does not undergo a global conformational change upon glucan binding but instead undergoes minimal rearrangement upon binding. The CBM has improved protection from deuteration when bound to glucans, confirming its role in glucan binding. More interestingly, we identified structural components of the DSP that also have improved protection from deuteration upon glucan addition. To determine the position of these regions, we generated a homology model of the SEX4 DSP. The homology model shows that all of these regions are adjacent to the DSP active site. Therefore, our results suggest that these regions of the DSP participate in the presentation of the phosphoglucan to the active site and provide the first structural analysis and mode of action of this unique class of phosphatases.

Dataset Information

Investigating the dynamics and polyanion binding sites of fibroblast growth factor-1 using hydrogen-deuterium exchange mass spectrometry.

Publications

Investigating the dynamics and polyanion binding sites of fibroblast growth factor-1 using hydrogen-deuterium exchange mass spectrometry.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets