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Origin of octameric creatine kinases
Author(s) -
Ellington W.Ross,
Roux Kenneth,
Pineda Agustin O
Publication year - 1998
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/s0014-5793(98)00204-x
Subject(s) - biology , creatine kinase , protein subunit , biochemistry , sperm , isozyme , microbiology and biotechnology , enzyme , gene , genetics
Mitochondrial creatine kinase (MiCK) occurs primarily as an octameric form localized in the mitochondrial intermembrane compartment in vertebrate tissues and echinoderm spermatozoa (both deuterostome groups). The octameric quaternary structure is thought to play important functional and enzyme targeting roles. We have found that the spermatozoa of the protostome polychaete Chaetopterus variopedatus contain three distinct isoenzymes of creatine kinase (CK) termed CK1, CK2 and CK3. CK3 appears to be present only in the sperm head/midpiece complex where mitochondria are restricted and has a subunit relative molecular mass ( M r ) of 43.4 kDa. Gel permeation chromatography using Superdex 200HR showed that CK3 has a native M r of 344.9 kDa indicating that this enzyme exists as an octamer. Electron micrographs of negatively stained CK3 preparations show structures which are virtually identical to those that have been seen for octameric vertebrate MiCK. The above observations show that CK3 from C. variopedatus displays great similarities to MiCKs from vertebrates and echinoderms. Octamerization of CK is not an advanced feature. The evolution of octameric subunit association is ancient and occurred prior to the divergence of protostomes and deuterostomes.