title: Nongenetic variation, genetic-environmental interactions and altered gene expression. III. Posttranslational modifications.
abstract: The use of protein electrophoretic data for determining the relationships among species or populations is widespread and generally accepted. However, posttranslational modifications have been discovered in many of the commonly analyzed proteins and enzymes. Posttranslational modifications often alter the electrophoretic mobility of the modified enzyme or protein. Because posttranslational modifications may affect only a fraction of the total enzyme or protein, an additional staining band often appears on gels as a result, and this may confound interpretations. Deamidation, acteylation, proteolytic modification, and oxidation of sulfhydryl groups are modifications that often result in an electrophoretic mobility shift. Sialic acid-induced heterogeneity has been documented for many enzymes, but neuraminidase treatment can often remove sialic acids and produce gel patterns that are easier to interpret. In some cases, ontogenetic and tissue-specific expression may be due to posttranslational modifications rather than gene control and restricted expression, respectively. Methods of preventing, detecting and eliminating posttranslational modifications are discussed. Some posttranslational modifications may be useful for detecting cryptic genetic polymorphisms.
authors.affiliation: Department of Zoology, Southern Illinois University, Carbondale, 62901-6501, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Poly
mesh_terms: D000064:Acclimatization; D000818:Animals; D004586:Electrophoresis; D004777:Environment; D015870:Gene Expression; D014644:Genetic Variation; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011110:Polymorphism, Genetic; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D011506:Proteins