Expression, Purification and Characterization of a Novel Rusticyanin from the Psychrotolerant <i>Acidithiobacillus ferrivorans</i>
Yuandong Liu,
Lixiang Chen,
Xiangdong Shangguan,
Jingying Ouyang,
Jiayu He,
Kan Wang,
Yan Tong,
Runlan Yu,
Weimin Zeng,
Xueling Wu,
Li Shen,
Guanzhou Qiu
Affiliations
Yuandong Liu
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Lixiang Chen
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Xiangdong Shangguan
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Jingying Ouyang
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Jiayu He
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Kan Wang
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Yan Tong
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Runlan Yu
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Weimin Zeng
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Xueling Wu
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Li Shen
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Guanzhou Qiu
Key Laboratory of Biohydrometallurgy of Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Rusticyanin plays a crucial role in ferrous oxidation of sulfide minerals during bioleaching for industrial metal extraction. Diverse isoforms of rusticyanin have been found, but until now, except for type-A rusticyanin, other isoforms or sources of rusticyanin have been scarcely investigated. Here, a rusticyanin (gene locus 0470) from the psychrophilic Acidithiobacillus ferrivorans was gene-cloned, expressed, purified, and assembled in vitro. All forms of the protein exhibit extreme acid stability, even at pH 0.3. The stability of the protein is obviously enhanced after binding of the copper cofactor; the oxidation state is more stable than the reduced state. The protein has characteristic UV-vis peaks and EPR signals similar to type-A or type-B rusticyanin but is different with a small position shift and an obvious intensity change. The vibrational spectrum of the apoprotein was more different than these between the oxidation and reduced states of the protein. The ferrous oxidation kinetic rate constant of the protein is obviously faster than that of both the type-A and type-B rusticyanins previously reported. Further bioinformatics analysis reveal their changes in sequence and molecule: the mutations related to the peculiar shield belt mostly account for the variation in the properties of the protein, and the classification of the protein as a new isoform, type-C rusticyanin, is proposed.
