Related Experiment Video
Updated: May 12, 2026
Digital Spatial Profiling for Characterization of the Microenvironment in Adult-Type Diffusely Infiltrating Glioma
Published on: September 13, 2022
Structural investigation of tumor differentiation factor
Urmi Roy1, Izabela Sokolowska, Alisa G Woods
1Biochemistry & Proteomics Group, Department of Chemistry & Biomolecular Science, Clarkson University, Potsdam, NY, USA.
Abstract:
Tumor differentiation factor (TDF) is a 17 kDa protein produced by the pituitary and secreted into the bloodstream, with no definitive function and incomplete characterization. TDF has the following four cysteine (Cys) residues: Cys17, Cys70, Cys97, and Cys98. To understand the function of TDF, we (1) overexpressed and characterized recombinant TDF (rTDF); (2) investigated native, secreted TDF; and (3) assessed potential disulfide connectivities using molecular modeling. Our results from Western blotting (WB) experiments suggest that rTDF is mostly expressed as insoluble, monomeric, and dimeric forms. Mass spectrometry analysis of the overexpressed rTDF identified a peptide that is a part of TDF protein. WB of the native, secreted TDF detected it as a 50 kDa band. In addition, investigation of TDF by molecular modeling suggests that the Cys residues may form disulfide bridges between Cys17-Cys98 and Cys70-Cys17.
Insights
Tumor differentiation factor (TDF), a pituitary protein, was studied for its function. Recombinant TDF (rTDF) showed varied expression, while native TDF appeared as a 50 kDa band, suggesting complex disulfide bonding.
Area of Science:
- Biochemistry
- Molecular Biology
- Proteomics
Background:
- Tumor differentiation factor (TDF) is a 17 kDa pituitary protein with unknown function.
- TDF contains four cysteine residues (Cys17, Cys70, Cys97, Cys98) crucial for protein structure and function.
- Incomplete characterization necessitates further investigation into TDF's properties and biological role.
Purpose of the Study:
- To overexpress and characterize recombinant TDF (rTDF).
- To investigate the properties of native, secreted TDF.
- To predict potential disulfide connectivities within TDF using molecular modeling.
Main Methods:
- Recombinant TDF (rTDF) overexpression and characterization.
- Western blotting (WB) for rTDF and native TDF detection.
- Mass spectrometry for rTDF peptide identification.
- Molecular modeling for disulfide bridge prediction.
Main Results:
- rTDF was predominantly expressed as insoluble monomers and dimers.
- Mass spectrometry confirmed the presence of a TDF peptide.
- Native, secreted TDF was detected as a 50 kDa band via WB.
- Molecular modeling suggested potential disulfide bridges between Cys17-Cys98 and Cys70-Cys17.
Conclusions:
- The study provides initial characterization of TDF, including its expression patterns and potential structural features.
- Discrepancies in molecular weight between recombinant and native TDF suggest post-translational modifications or complex folding.
- Predicted disulfide bridges offer insights into TDF's tertiary structure and potential function.
