Studies on the sub-banding of creatine kinase MM and the “CK conversion factor”

Falter, H.; Michelutti, Lisa; Mazzuchin, A.; Whiston, W.

doi:10.1016/0009-9120(81)90030-8

Cited by 32 publications

(4 citation statements)

References 24 publications

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“…After this first purification step albumin appeared to be the major contaminating protein (Fig. 3.1) due to its pZ value of 4.7 [8], which is in the vicinity of that of the modifying protein (4.35). The second purification step was, therefore, based on separation in molecular mass (albumin is 67 000; modifying protein is 185 000).…”

Section: Resultsmentioning

confidence: 99%

Purification and determination of the modifying protein responsible for the post-synthetic modification of creatine kinase (EC 2.7.3.2) and enolase(EC 4.2.1.11)

Landeghem

Soons

Wever

et al. 1985

Clinica Chimica Acta

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SummaryThe purification of a serum protein, responsible for the postsynthetic modification of CK and enolase, is described. A purification of about 1300-fold could be reached after subsequent chromatography of human serum on DEAE cellulose and Sephacryl S-200 Superfine followed by affinity chromatography using antibodies against human serum albumin, C3 and C4 and against total human serum proteins. A recovery of 160% of modifying activity was found. The molecular mass and the isoelectric point of the modifying protein have been determined.It is concluded that the concentration of the modifying protein in human serum is < 210 mg/l.

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Section: Resultsmentioning

confidence: 99%

Purification and determination of the modifying protein responsible for the post-synthetic modification of creatine kinase (EC 2.7.3.2) and enolase(EC 4.2.1.11)

Landeghem

Soons

Wever

et al. 1985

Clinica Chimica Acta

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“…The M, has been determined as 190000 (Falter et al, 1981), which is significantly larger than those of the pancreatic carboxypeptidases A and B, at 34400 and 34000 respectively (Hartsuck & Lipscomb. 1971;Folk, 1971).…”

Section: Discussionmentioning

confidence: 99%

Human ‘creatine kinase conversion factor’ identified as a carboxypeptidase

Edwards¹,

Watts²

1984

Biochemical Journal

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The effect of partially purified 'creatine kinase conversion factor' on rabbit muscle creatine kinase is shown to be that of a carboxypeptidase, removing the C-terminal lysine residue from both subunits. These changes fully explain the three-banded electrophoretic patterns of the partially and the fully modified rabbit and human enzymes. The factor also produces a similar electrophoretic pattern with haemoglobin A; comparison with the effects of carboxypeptidases A and B permits the inference that the C-terminal residues of both alpha- and beta-subunits are removed. Small synthetic peptides are poor or non-substrates. A low activity with hippuryl-L-lysine may be due to contamination of the preparation with carboxypeptidase N. The possibility has been excluded that the action of conversion factor on creatine kinase involves modification of the protein thiol groups. Mr, substrate-specificity, pH-activity profile and the effects of metal ions distinguish creatine kinase conversion factor from carboxypeptidases A, B and N. On the basis of this evidence it is proposed to give the conversion factor the provisional name of carboxypeptidase K.

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“…The ageing of the enzyme can be attributed to a modification in the M-chain caused by a serum protein [1,2], for which the name CK conversion factor has been proposed [3]. As the same protein modifies the alpha chain of enolase as well [7], the name modifying protein was introduced by Wevers et al [7], Recently, the modifying protein has been shown to have carboxypeptidase activity [8,9].…”

Section: Introductionmentioning

confidence: 99%

Indices for the age of the creatine kinase M-chain in the blood

Wevers

Hagelauer

Stein

et al. 1985

Clinica Chimica Acta

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SummaryThe apparent activation energy of the CK reaction as well as the Michaelis-Menten constants and the isoelectric point of CK MM can be used as indices for the mean age of the CK M-chain in the blood in vivo and in vitro. Modifications in the CK M-chain take place in vivo in the blood and in vitro in a serum matrix. Gradual increases in the apparent activation energy are also observed both in vivo and in vitro. It is confirmed that the modification in the CK M-chain causes a rise in the apparent activation energy, u.A gradual increase in apparent activation energy, due to the ageing process of the CK M-chain, was observed after myocardial infarction. A significantly increased value for u was observed at the time that total CK activity already had returned to reference values. In spite of the normal CK value, the apparent activation energy still indicated that there had been myocardial damage. The Michaelis-Menten constants for creatine phosphate and ADP are also influenced significantly by the modification in the M-chain. While the apparent activation energy increases, the Michaelis constants decrease in the order MM,, MM,, MM,. The Michaelis-Menten constants for both ADP and CrP can be used as an index for the mean age of the enzyme in the blood.The Michaelis-Menten constants for CrP and ADP show significant variations with the measuring temperature for virtually all CK MM forms.

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Studies on the sub-banding of creatine kinase MM and the “CK conversion factor”

Cited by 32 publications

References 24 publications

Purification and determination of the modifying protein responsible for the post-synthetic modification of creatine kinase (EC 2.7.3.2) and enolase(EC 4.2.1.11)

Purification and determination of the modifying protein responsible for the post-synthetic modification of creatine kinase (EC 2.7.3.2) and enolase(EC 4.2.1.11)

Human ‘creatine kinase conversion factor’ identified as a carboxypeptidase

Indices for the age of the creatine kinase M-chain in the blood

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