Kinetics of Zn(2+)-induced brain type creatine kinase unfolding and aggregation.
We studied the effect of Zn(2+) on the folding and aggregation of brain creatine kinase (CK-BB). We developed a method to purify CK-BB from rabbit brain and conducted inhibition kinetics and unfolding studies of CK-BB. Zn(2+) conspicuously aggregated and osmolytes, such as glycine and proline, were able to suppress the formation of aggregates and protect the enzymatic activity against Zn(2+). These results suggest that Zn(2+) might act as a risk factor for CK-BB in the brain under certain conditions, and some osmolytes may help CK-BB to sustain the active state when Zn(2+) is present. Our study provides useful information regarding the effect of Zn(2+) on brain-derived metabolic enzymes, especially those that are putatively related to brain disease. Furthermore, our study suggests that although Zn(2+) may induce CK-BB inactivation and misfolding, the ability of some abundant proteins and osmolytes to chelate Zn(2+) nonspecifically may protect CK-BB and allow it to exist in the active form.
Mu
Hang
H
Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, People's Republic of China.
Lü
Zhi-Rong
ZR
Park
Daeui
D
Kim
Byoung-Chul
BC
Bhak
Jong
J
Zou
Fei
F
Yang
Jun-Mo
JM
Li
Sen
S
Park
Yong-Doo
YD
Zou
He-Chang
HC
Zhou
Hai-Meng
HM
D000818:Animals; D002942:Circular Dichroism; D052276:Creatine Kinase, BB Form / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D005453:Fluorescence; D005998:Glycine / Q000494:pharmacology; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D011392:Proline / Q000494:pharmacology; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011817:Rabbits; D013997:Time Factors; D015032:Zinc / Q000494:pharmacology*
D011392:Proline; D052276:Creatine Kinase, BB Form; D015032:Zinc; D005998:Glycine