Comparative Evaluation of Solid-phase and Membrane Mimetic Strategies in Membrane Proteome Coverage and Disease-State Analysis

Membrane proteins (MPs) are vital to cellular signaling, metabolism, and disease pathology, yet remain underrepresented in proteomics. To address this, several independent workflows have been developed to enable the profiling of the membrane proteome; however, the relative advantages and limitations of each method remain poorly defined. Here, we systematically compare four classical solid-phase membrane proteomic workflows (SP3, SP4, FASP, S-Trap) and three membrane mimetic strategies (Peptidisc, nanodisc, and SMALP copolymer) for mass spectrometry-based membrane proteome profiling, using healthy (LFD) and obese (HFD) mouse liver tissue. We found that the solid-phase methods yield higher total protein identifications, while the membrane mimetic systems enrich MPs. SMALP copolymer displays intermediate characteristics between the solid-phase and membrane mimetic workflows. Peptidisc and nanodisc stand out for their enrichment of MPs, although Peptidisc shows better enrichment of plasma membrane integral MPs, particularly those with 11+ transmembrane segments. In the context of HFD-induced liver proteome remodeling, the Peptidisc workflow outperformed the other six methods by capturing the highest number of differentially expressed MPs and demonstrating the lowest standard deviation of MP-level dysregulation. Collectively, this comparative analysis highlights the trade-offs between depth of proteome coverage and MP enrichment across workflows, underscoring the importance of method selection based on total protein counts, MP enrichment, and the precise detection of MP-level dysregulation.