@article {ijms221810012,
	title = {Enhanced Stability of Detergent-Free Human Native STEAP1 Protein from Neoplastic Prostate Cancer Cells upon an Innovative Isolation Procedure},
	journal = {International Journal of Molecular Sciences},
	volume = {22},
	number = {18},
	year = {2021},
	note = {n/a},
	abstract = {<p>Background: The STEAP1 is a cell-surface antigen over-expressed in prostate cancer, which contributes to tumor progression and aggressiveness. However, the molecular mechanisms underlying STEAP1 and its structural determinants remain elusive. Methods: The fraction capacity of Butyl- and Octyl-Sepharose matrices on LNCaP lysates was evaluated by manipulating the ionic strength of binding and elution phases, followed by a Co-Immunoprecipitation (Co-IP) polishing. Several potential stabilizing additives were assessed, and the melting temperature (Tm) values ranked the best/worst compounds. The secondary structure of STEAP1 was identified by circular dichroism. Results: The STEAP1 was not fully captured with 1.375 M (Butyl), in contrast with interfering heterologous proteins, which were strongly retained and mostly eluted with water. This single step demonstrated higher selectivity of Butyl-Sepharose for host impurities removal from injected crude samples. Co-IP allowed recovering a purified fraction of STEAP1 and contributed to unveil potential physiologically interacting counterparts with the target. A Tm of ~55 {\textdegree}C was determined, confirming STEAP1 stability in the purification buffer. A predominant α-helical structure was identified, ensuring the protein{\textquoteright}s structural stability. Conclusions: A method for successfully isolating human STEAP1 from LNCaP cells was provided, avoiding the use of detergents to achieve stability, even outside a membrane-mimicking environment.</p>
},
	issn = {1422-0067},
	doi = {10.3390/ijms221810012},
	url = {https://www.mdpi.com/1422-0067/22/18/10012},
	author = {Barroca-Ferreira, Jorge and Cruz-Vicente, Pedro and Santos, Marino F. A. and Rocha, Sandra M. and Santos-Silva, Teresa and Maia, Cl{\'a}udio J. and Passarinha, Lu{\'\i}s A.}
}
