isoelectric point

isoelectric point
The pH at which a protein carries no net charge. Below the isoelectric point proteins carry a net positive charge; above it a net negative charge. Due to a preponderance of weakly acid residues in almost all proteins, they are nearly all negatively charged at neutral pH. The isoelectric point is of significance in protein purification because it is the pH at which solubility is often minimal, and at which mobility in an electrofocusing system is zero (and therefore the point at which the protein will accumulate).

Dictionary of molecular biology. 2004.

Look at other dictionaries:

  • isoelectric point — [ī΄sōē lek′trikpoint, ī΄səə lek′trik] n. the point, or pH value, at which a substance is neutral or has zero electric potential …   English World dictionary

  • isoelectric point — isoelectric point. См. изоэлектрическая точка. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Isoelectric point — The isoelectric point (pI) is the pH at which a particular molecule or surface carries no net electrical charge. Amphoteric molecules called zwitterions contain both positive and negative charges depending on the functional groups present in the… …   Wikipedia

  • isoelectric point — noun : the point or narrow range on a pH scale at which the concentration of anionic part of an ampholyte equals that of the cationic part : the pH at which the ampholyte will not migrate in an electrical field the isoelectric points of most… …   Useful english dictionary

  • isoelectric point — izoelektrinis taškas statusas T sritis chemija apibrėžtis Tirpalo pH vertė, kuriai esant poliamfolito ar koloidinės dalelės suminis krūvis lygus nuliui. atitikmenys: angl. isoelectric point rus. изоэлектрическая точка …   Chemijos terminų aiškinamasis žodynas

  • isoelectric point — Chem. the pH at which a substance is electrically neutral or at which it is at its minimum ionization. [1895 1900] * * * …   Universalium

  • isoelectric point — noun the pH of a colloidal suspension or of an ampholyte at which the solute does not move in an electrophoretic field …   Wiktionary

  • isoelectric point — the pH of a solution at which a charged molecule does not migrate in an electric field …   Medical dictionary

  • isoelectric point — /ˌaɪsoʊəˈlɛktrɪk pɔɪnt/ (say .uysohuh lektrik poynt) noun the pH at which a substance is electrically neutral or least ionised …   Australian English dictionary

  • Isoelectric focusing — (IEF), also known as electrofocusing, is a technique for separating different molecules by their electric charge differences. It is a type of zone electrophoresis, usually performed in a gel, that takes advantage of the fact that a molecule s… …   Wikipedia


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