title: Proteomic analysis of mice expressing human ApoE demonstrates no differences in global protein solubility between APOE 3 and APOE 4 young mice.
abstract: Apolipoprotein E (ApoE) is a major lipid carrier protein. In humans, ApoE is expressed in three polymorphic isoforms, which are encoded by three different alleles APOE2, APOE3, and APOE4. In the brains of Alzheimer's disease (AD) patients, each one of these three allelic isoforms is found in several "isoelectric" protein isoforms (qPI), i.e. protein isoforms resulting from PTMs altering the net charge (q) of the polypeptide. AD is a complex disease in which multiple causes and several risk factors affect the onset and disease outcome. A major risk factor for AD is ApoE4; therefore, it is important to characterize the different ApoE qPIs. We have implemented a detergent-based method for isolation and quantitation of protein isoforms, and we found differences in the solubility of protein isoforms depending on the type of solvent used. In this manuscript, we describe these methods and applied them to young human-ApoE targeted replacement mice. Our results indicate that there are no significant differences in the hippocampus proteome of these mice as a function of the APOE genotype.
authors.affiliation: Systems Proteomics Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Carolina
authors.initials: C
authors.lastname: Londono
authors.forename: Robert M
authors.initials: RM
authors.lastname: DeKroon
authors.forename: Mihaela
authors.initials: M
authors.lastname: Mocanu
authors.forename: Jessica
authors.initials: J
authors.lastname: Booe
authors.forename: Witold M
authors.initials: WM
authors.lastname: Winnik
authors.forename: Adam
authors.initials: A
authors.lastname: Swank
authors.forename: Cristina
authors.initials: C
authors.lastname: Osorio
authors.forename: Eric D
authors.initials: ED
authors.lastname: Hamlett
authors.forename: Oscar
authors.initials: O
authors.lastname: Alzate
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D053318:Apolipoprotein E3 / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D053327:Apolipoprotein E4 / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D003402:Creatine Kinase / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005838:Genotype; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D010751:Phosphopyruvate Hydratase / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D020033:Protein Isoforms; D020543:Proteome / Q000032:analysis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D012995:Solubility
chemical_list: D053318:Apolipoprotein E3; D053327:Apolipoprotein E4; D020033:Protein Isoforms; D020543:Proteome; D003402:Creatine Kinase; D010751:Phosphopyruvate Hydratase