Complexes of creatine kinase and immunoglobulins in serum identified by a nonimmune binding method.
We have developed a method for identifying IgG-complexed creatine kinase (CK; EC 2.7.3.2) (IgG-CK) and IgA-complexed CK (IgA-CK) in serum. We used immobilized Protein G to bind IgG-CK and immobilized jacalin to bind IgA-CK, leaving noncomplexed CK in solution. The noncomplexed CK and total CK were measured kinetically. The results are reported as CK bound to immobilized Protein G and CK bound to immobilized jacalin. We validated the method by using sera determined immunochemically to contain IgG-CK, IgA-CK, mitochondrial CK (CKmt), and free CK-BB. We demonstrated concomitant binding of CK and approximately 99% of IgG, and of CK and approximately 87% of IgA. For CK bound to immobilized Protein G and to immobilized jacalin, intra- and interassay precisions ranged from 2.5% to 9.6%, and detection limits were less than 9 318 U/L in 40 sera containing IgG-CK, and CK bound to immobilized jacalin ranged from 10 to 59 U/L in eight sera containing IgA-CK. These ranges represent the activities of immunoglobulin-bound CK in the sera. In 13 sera containing CKmt and in eight sera containing free CK-BB, the binding of CK was less than 9 U/L. Evidently, this method is useful for identifying IgG-CK and IgA-CK in serum.
Backer
E T
ET
Department of Clinical Chemistry, Het, Diaconessenhuis, Leiden, The Netherlands.
Hafkenscheid
J C
JC
van Wermeskerken
R K
RK
D003402:Creatine Kinase / Q000097:blood* / Q000378:metabolism; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D007074:Immunoglobulin G / Q000378:metabolism*; D007369:Interferon Inducers / Q000378:metabolism; D007527:Isoenzymes / Q000097:blood* / Q000378:metabolism; D037102:Lectins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D037121:Plant Lectins; D011233:Precipitin Tests
C029152:G-substrate; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007369:Interferon Inducers; D007527:Isoenzymes; D037102:Lectins; D009419:Nerve Tissue Proteins; D037121:Plant Lectins; C043696:jacalin; D003402:Creatine Kinase