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Detection and investigation of the molecular nature of low‐molecular‐mass copper ions in isolated rheumatoid knee‐joint synovial fluid
Author(s) -
Naughton Declan P.,
Knappitt Jacky,
Fairburn Kevin,
Gaffney Karl,
Blake David R.,
Grootveld Martin
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00165-6
Subject(s) - chemistry , histidine , copper , molecular mass , formate , context (archaeology) , tyrosine , synovial fluid , nuclear chemistry , amino acid , biochemistry , organic chemistry , osteoarthritis , medicine , pathology , biology , enzyme , catalysis , paleontology , alternative medicine
Low‐molecular‐mass copper(II) species have been detected and quantified in ultrafiltrates ( n = 7) of rheumatoid synovial fluid (SF) by a highly‐sensitive HPLC‐based assay system with the ability to determine Cu(II) concentrations of < 10 −7 mol·dm t ‐3 . High field 1 H NMR spectroscopy demonstrated that addition of Cu(II) (aq.) to isolated samples of RA SF ultrafiltrates resulted in complexation by histidine > alanine > formate > threonine > lactate > tyrosine > phenylalanine, their effectiveness in this context being in the given order. CD spectra of Cu(II)‐treated samples of intact SF exhibited absorption bands typical of copper(II)‐albumin complexes, in addition to a band attributable to a low‐molecular‐mass histidinate complex ( λ min 610 nm). Since both albumin and histidine are potent radical scavengers, these results indicate that any . OH radical generated from bound copper ions will be ‘site‐specifically’ scavenged. Hence, low‐molecular‐mass copper complexes with the ability to promote the generation of . OH radical which can then escape from the metal ion co‐ordination sphere (and in turn, cause damage to critical biomolecules) appear to be absent from inflammatory SF.