Effect of pH and ionic strength on μ- and m-calpain inhibition by calpastatin

dc.contributor.author Lonergan, Steven
dc.contributor.author Maddock, K.
dc.contributor.author Huff-Lonergan, Elisabeth
dc.contributor.author Huff-Lonergan, Elisabeth
dc.contributor.author Rowe, L.
dc.contributor.author Lonergan, Steven
dc.contributor.department Animal Science
dc.date 2018-02-13T21:49:44.000
dc.date.accessioned 2020-06-29T23:39:20Z
dc.date.available 2020-06-29T23:39:20Z
dc.date.copyright Sat Jan 01 00:00:00 UTC 2005
dc.date.embargo 2014-02-24
dc.date.issued 2005-06-01
dc.description.abstract <p>The objectives of this study were to determine the extent to which pH and ionic strength influence μ- and m-calpain activity and the inhibition of calpains by calpastatin. Calpastatin, μ-calpain, and m-calpain were purified from at-death porcine semimembranosus. μ-Calpain or m-calpain (0.45 U) were incubated with the calpain substrate Suc-Leu-Leu-Val-Tyr-7-amino-4-methyl coumarin in the presence of calpastatin (0, 0.15, or 0.30 U of calpain inhibitory activity) under the following pH and ionic strength conditions: pH 7.5 and 165 m<em>M</em> NaCl or 295 m<em>M</em> NaCl; pH 6.5 and 165 m<em>M</em> NaCl or 295 m<em>M</em> NaCl; and pH 6.0 and 165 m<em>M</em> NaCl or 295 m<em>M</em> NaCl. The reactions were initiated with addition of 100 μ<em>M</em> (μ-calpain) or 1 m<em>M</em> CaCl<sub>2</sub> (m-calpain), and calpain activity was recorded at 30 and 60 min. μ-Calpain had the greatest (<em>P</em> < 0.01) activity at pH 6.5 at each ionic strength. Higher ionic strength decreased μ-calpain activity (<em>P</em>< 0.01) at all pH conditions. Inhibition percent of μ-calpain by calpastatin was not affected by pH; however, it was influenced by ionic strength. Inhibition of μ-calpain by calpastatin was higher (<em>P</em> < 0.01) at 295 m<em>M</em> NaCl than at 165 m<em>M</em> NaCl when 0.3 units of calpastatin were included in the assay. Activity of m-calpain was greater (<em>P</em> < 0.01) at pH 7.5 than at pH 6.5. m-Calpain activity was not detected at pH 6.0. Inhibition of m-calpain was greater (<em>P</em> < 0.01) when 0.15 and 0.3 U calpastatin were added at pH 6.5 than 7.5 at 165 m<em>M</em> NaCl, whereas percentage inhibition of m-calpain was greater (<em>P</em> < 0.01) at 295 m<em>M</em> than 165 m<em>M</em> NaCl at pH 7.5 and 6.5. These observations provide new evidence that defines further the influence of pH decline and increased ionic strength on μ-calpain, m-calpain, and calpastatin activity, thereby helping to more accurately define a role for these enzymes in the process of postmortem tenderization.</p>
dc.description.comments <p>This article is from <em>Journal of Animal Science</em> 83 (2005): 1370–1376. Posted with permission.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/ans_pubs/25/
dc.identifier.articleid 1019
dc.identifier.contextkey 5193955
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath ans_pubs/25
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/9658
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/ans_pubs/25/2005_MaddockKR_EffectpHIonic.pdf|||Fri Jan 14 22:55:36 UTC 2022
dc.subject.disciplines Agriculture
dc.subject.disciplines Animal Sciences
dc.subject.disciplines Meat Science
dc.subject.keywords calpain
dc.subject.keywords calpastatin
dc.subject.keywords ionic strength
dc.subject.keywords proteolysis
dc.subject.keywords pH
dc.title Effect of pH and ionic strength on μ- and m-calpain inhibition by calpastatin
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication 8e04bc80-6e32-476c-a184-b0311cebe213
relation.isAuthorOfPublication 6a8e1178-0f76-46eb-bf7a-9f871232456b
relation.isOrgUnitOfPublication 85ecce08-311a-441b-9c4d-ee2a3569506f
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