Unha '''proteína integral de membrana''' é un tipo de [[proteína de membrana]] que está unida de forma permanente a unha [[membrana celular]]. As proteínas que están integradas na membrana están rodeadas por lípidos, cos que están en directo contacto. As proteínas integrais só poden ser separadas da membrana utilizando [[deterxente]]s, [[solvente non polar|solventes non polares]], ou ás veces axentes [[Desnaturalización (bioquímica|desnaturalizantes]].
An '''integral membrane protein''' ('''IMP''') is a type of [[membrane protein]] that is permanently attached to the [[biological membrane]]. Proteins that cross the membrane are surrounded by "annular" lipids, which are defined as lipids that are in direct contact with a membrane protein. Such proteins can be separated from the biological membranes only using [[detergent]]s, [[nonpolar solvent]]s, or sometimes [[Denaturation (biochemistry)|denaturing]] agents.
IMPsAs compriseproteínas aintegrais veryde significantmembrana fractionson ofunha thefracción proteinsmoi encodedsignificativa indas anproteínas organism'scodificadas no [[genome]xenoma]+ dun organismo.<ref>{{cite journal |author=Wallin E, von Heijne G |title=Genome-wide analysis of integral membrane proteins from eubacterial, archaean, and eukaryotic organisms |journal=Protein Science |volume=7 |issue=4 |pages=1029–38 |year=1998 |pmid=9568909 |pmc=2143985 |doi=10.1002/pro.5560070420}}</ref>
AllTodas as [[transmembraneproteina proteintransmembrana|proteínas transmembrana]]sareson IMPsproteínas integrais de membrana, butpero non todas as integras son transmembrana, xa que moitas non atravesan nota allmembrana IMPsdun arelado transmembranea proteinsoutro.<ref name="Goodman2008">{{cite book|author=Steven R. Goodman|title=Medical cell biology|url=http://books.google.com/books?id=WO6EVUgWw7AC&pg=PA37|accessdate=24 November 2010|year=2008|publisher=Academic Press|isbn=978-0-12-370458-0|pages=37–}}</ref>
==StructureEstrutura==
Three-dimensional structures of only ~160 different integral membrane proteins are currently determined at atomic resolution by [[X-ray crystallography]] or [[nuclear magnetic resonance]] [[spectroscopy]] due to the difficulties with extraction and [[Crystallization adjutant|crystallization]]. In addition, structures of many water-soluble domains of IMPs are available in the [[Protein Data Bank]]. Their membrane-anchoring α-helices have been removed to facilitate the extraction and [[Protein crystallization|crystallization]]. Search [http://www.ebi.ac.uk/pdbe-srv/PDBeXplore/go/?GO=go:0016021 integral membrane proteins] in the PDB (based on [[gene ontology]] classification)
