TY - JOUR
T1 - Disulfide bond and crosslinking analyses reveal inter-domain interactions that contribute to the rigidity of placental malaria VAR2CSA structure and formation of CSA binding channel
AU - Jagadeeshaprasad, Mashanipalya G.
AU - Gautam, Lovely
AU - Bewley, Maria C.
AU - Goel, Suchi
AU - Akhouri, Reetesh R.
AU - Gowda, D. Channe
N1 - Funding Information:
This work was supported by the National Institute of Allergy and Infectious Diseases, National Institutes of Health , Grant R01 R01AI104844 (to DCG). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Funding Information:
We thank Dr. Bruce Stanley and the staff at the Mass Spectrometry and Proteomics Core of the Penn State College of Medicine for their assistance with LC-MS/MS and data collection. Mass Spectrometry and Proteomics Core (RRID: SCR_017831 ) services and instruments used in this project were funded, in part, by The Pennsylvania State University College of Medicine via the Office of the Vice Dean of Research and Graduate Students and the Pennsylvania Department of Health using Tobacco Settlement Funds (CURE). The content is solely the responsibility of the authors and does not necessarily represent the official views of the University or College of Medicine. The Pennsylvania Department of Health specifically disclaims responsibility for any analyses, interpretations, or conclusions.
Funding Information:
We thank Dr. Bruce Stanley and the staff at the Mass Spectrometry and Proteomics Core of the Penn State College of Medicine for their assistance with LC-MS/MS and data collection. Mass Spectrometry and Proteomics Core (RRID:SCR_017831) services and instruments used in this project were funded, in part, by The Pennsylvania State University College of Medicine via the Office of the Vice Dean of Research and Graduate Students and the Pennsylvania Department of Health using Tobacco Settlement Funds (CURE). The content is solely the responsibility of the authors and does not necessarily represent the official views of the University or College of Medicine. The Pennsylvania Department of Health specifically disclaims responsibility for any analyses, interpretations, or conclusions. This work was supported by the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Grant R01 R01AI104844 (to DCG). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Publisher Copyright:
© 2022 The Authors
PY - 2023/1/31
Y1 - 2023/1/31
N2 - VAR2CSA, a multidomain Plasmodium falciparum protein, mediates the adherence of parasite-infected red blood cells to chondroitin 4-sulfate (C4S) in the placenta, contributing to placental malaria. Therefore, detailed understanding of VAR2CSA structure likely help developing strategies to treat placental malaria. The VAR2CSA ectodomain consists of an N-terminal segment (NTS), six Duffy binding-like (DBL) domains, and three interdomains (IDs) present in sequence NTS-DBL1x-ID1-DBL2x-ID2-DBL3x-DBL4ε-ID3-DBL5ε-DBL6ε. Recent electron microscopy studies showed that VAR2CSA is compactly organized into a globular structure containing C4S-binding channel, and that DBL5ε-DBL6ε arm is attached to the NTS-ID3 core structure. However, the structural elements involved in inter-domain interactions that stabilize the VAR2CSA structure remain largely not understood. Here, limited proteolysis and peptide mapping by mass spectrometry showed that VAR2CSA contains several inter-domain disulfide bonds that stabilize its compact structure. Chemical crosslinking-mass spectrometry showed that all IDs interact with DBL4ε; additionally, IDs interact with other DBL domains, demonstrating that IDs are the key structural scaffolds that shape the functional NTS-ID3 core. Ligand binding analysis suggested that NTS considerably restricts the C4S binding. Overall, our study revealed that inter-domain disulfide bonds and interactions between IDs and DBL domains contribute to the stability of VAR2CSA structural architecture and formation of C4S-binding channel.
AB - VAR2CSA, a multidomain Plasmodium falciparum protein, mediates the adherence of parasite-infected red blood cells to chondroitin 4-sulfate (C4S) in the placenta, contributing to placental malaria. Therefore, detailed understanding of VAR2CSA structure likely help developing strategies to treat placental malaria. The VAR2CSA ectodomain consists of an N-terminal segment (NTS), six Duffy binding-like (DBL) domains, and three interdomains (IDs) present in sequence NTS-DBL1x-ID1-DBL2x-ID2-DBL3x-DBL4ε-ID3-DBL5ε-DBL6ε. Recent electron microscopy studies showed that VAR2CSA is compactly organized into a globular structure containing C4S-binding channel, and that DBL5ε-DBL6ε arm is attached to the NTS-ID3 core structure. However, the structural elements involved in inter-domain interactions that stabilize the VAR2CSA structure remain largely not understood. Here, limited proteolysis and peptide mapping by mass spectrometry showed that VAR2CSA contains several inter-domain disulfide bonds that stabilize its compact structure. Chemical crosslinking-mass spectrometry showed that all IDs interact with DBL4ε; additionally, IDs interact with other DBL domains, demonstrating that IDs are the key structural scaffolds that shape the functional NTS-ID3 core. Ligand binding analysis suggested that NTS considerably restricts the C4S binding. Overall, our study revealed that inter-domain disulfide bonds and interactions between IDs and DBL domains contribute to the stability of VAR2CSA structural architecture and formation of C4S-binding channel.
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U2 - 10.1016/j.ijbiomac.2022.11.258
DO - 10.1016/j.ijbiomac.2022.11.258
M3 - Article
C2 - 36470436
AN - SCOPUS:85143721689
SN - 0141-8130
VL - 226
SP - 143
EP - 158
JO - International Journal of Biological Macromolecules
JF - International Journal of Biological Macromolecules
ER -