{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T19:34:20Z","timestamp":1787686460312,"version":"build-2784847793"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"2","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1996,4,15]]},"abstract":"<jats:p>Lipopolysaccharide (LPS), the major cell wall constituent of Gram-negative bacteria, evokes a multitude of biological effects in mammals including pyrogenicity and toxic shock syndrome. Polymyxin B (PmB), a polycationic cyclic peptide, is known to neutralize most of its activities. The nature of the interaction of PmB with LPS and lipid A was investigated by isothermal titration calorimetry. PmB binds to LPS as well as lipid A stoichiometrically and non-co-operatively with micromolar affinity. These interactions are driven primarily by a favourable change in entropy (\u2206S) and are endothermic in nature. These positive changes in enthalpies decrease with increasing temperature, yielding a heat capacity change, \u2206Cp, of -2385 J\u00b7mol-1\u00b7degree-1 for PmB\u2013LPS interactions while the binding of PmB to lipid A displays a \u2206Cp of -2259 J\u00b7mol-1\u00b7degree-1. The negative heat capacity changes provide strong evidence for the role of hydrophobic interactions as the driving force for the association of PmB with LPS and lipid A. A correlation of the energetics of these interactions with analyses of the molecular models of PmB suggests that a cluster of solvent-exposed non-polar amino acid side-chains that line one surface of the molecule, together with a ring of positively charged residues on its other surface, are responsible for its strong and stoichiometric binding to LPS.<\/jats:p>","DOI":"10.1042\/bj3150679","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:48:38Z","timestamp":1439243318000},"page":"679-686","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":138,"title":["Titration calorimetric studies to elucidate the specificity of the interactions of polymyxin B with lipopolysaccharides and lipid A"],"prefix":"10.1042","volume":"315","author":[{"given":"Subita","family":"SRIMAL","sequence":"first","affiliation":[{"name":"Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Namita","family":"SUROLIA","sequence":"additional","affiliation":[{"name":"Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur Post, Bangalore 560 064, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.","family":"BALASUBRAMANIAN","sequence":"additional","affiliation":[{"name":"Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Avadhesha","family":"SUROLIA","sequence":"additional","affiliation":[{"name":"Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/315\/2\/679\/619798\/bj3150679.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/315\/2\/679\/619798\/bj3150679.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,24]],"date-time":"2021-11-24T00:14:17Z","timestamp":1637712857000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/315\/2\/679\/32881\/Titration-calorimetric-studies-to-elucidate-the"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1996,4,15]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1996,4,15]]}},"URL":"https:\/\/doi.org\/10.1042\/bj3150679","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1996,4,15]]}}}