title: Refolding of lactate dehydrogenase by zeolite beta.
abstract: We used zeolite beta as an adsorbing matrix to refold recombinant lactate dehydrogenase (LDH) protein collected as an insoluble aggregate from a bacterial expression system. The adsorption isotherm revealed that 1 g of zeolite adsorbed 200 mg of denatured LDH solubilized with a buffer containing 6 M of guanidine hydrochloride. The pH of the buffer had little effect on the adsorption, but this property was abolished by preincubation of the zeolite with polyethylene glycol (PEG) in a weight ratio of 1:10. These data suggest that the adsorption of LDH depends on the hydrophobicity of the zeolite surface, and that the adsorption of PEG to zeolite is sufficient to release LDH from its surface. LDH was thus released by refolding buffer containing PEG and arginine, and soluble LDH was obtained in its active enzymatic form. The addition of arginine dramatically increased the yield of LDH in a dose-dependent manner. The overall refolding efficiency was optimized to 35%.
authors.affiliation: Research Center for Compact Chemical Process, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Togashi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nara
authors.forename: Chisato
authors.initials: C
authors.lastname: Sekikawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kawakami
authors.forename: Nakatsugu
authors.initials: N
authors.lastname: Yaginuma
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Tsunoda
authors.forename: Kengo
authors.initials: K
authors.lastname: Sakaguchi
authors.forename: Fujio
authors.initials: F
authors.lastname: Mizukami
mesh_terms: D007770:L-Lactate Dehydrogenase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D017641:Zeolites / Q000737:chemistry*
chemical_list: D011994:Recombinant Proteins; D017641:Zeolites; D007770:L-Lactate Dehydrogenase