Isolation of GIF from porcine brain and studies of its zinc transfer kinetics with apo-carbonic anhydrase.
Neuronal growth inhibitory factor (GIF) of porcine brain, was isolated and purified by a similar procedure which was used on the isolation of human and bovine GIF. The native porcine protein with stoichiometry of 4Cu+, 3Zn2+ was obtained for the first time. The kinetics of zinc transfer from Cu4Zn3MT-3 to apo-carbonic anhydrase were studied, and zinc transfer rate constants and thermodynamic parameters were obtained. It is found that like other MTs, porcine Cu4Zn3MT-3 can also transfer its zinc atom to apoCA, even much easier than other MTs. A possible association mechanism has been proposed, the formation of Cu4Zn3MT3-apoCA complex may be the rate-determining step. The obtained data indicate besides its neuronal growth inhibitory function, GIF might play a role in cellular Zn homeostasis in brain.
Shi
Yan-bo
YB
State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Nanjing University, China.
Du
Liang
L
Zheng
Wei-juan
WJ
Tang
Wen-xia
WX
D000818:Animals; D001921:Brain / Q000201:enzymology / Q000378:metabolism; D002256:Carbonic Anhydrases / Q000378:metabolism*; D017136:Ion Transport; D007700:Kinetics; D008668:Metallothionein / Q000378:metabolism; D000090023:Metallothionein 3; D009419:Nerve Tissue Proteins / Q000302:isolation & purification* / Q000378:metabolism; D013053:Spectrophotometry; D013552:Swine / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
D000090023:Metallothionein 3; D009419:Nerve Tissue Proteins; D008668:Metallothionein; D002256:Carbonic Anhydrases; D015032:Zinc