Effects of C-terminal deletions on the conformational state and denaturation of phosphoglycerate kinase.
Effects of C-terminal deletions on the conformational state and denaturation of phosphoglycerate kinase.
复制标题
C 端缺失对磷酸甘油酸激酶构象状态和变性的影响。
DOI：
10.1021/bi00024a018
复制
发表时间：
1995
期刊：
影响因子：
2.9
通讯作者：
Brandts,JF
中科院分区：
文献类型：
--
作者：
Mas,MT;Chen,HH;Aisaka,K;Lin,LN;Brandts,JF
Revised Manuscript Received April 14, 1995® abstract: Phosphoglycerate kinase (PGK) contains two domains of approximately equal size, both of the ol//3 type. An a-helix consisting of the middle section of the 415-amino acid polypeptide chain, and the N-and C-termini reside in the interdomain hinge region [Watson, H. C., et al.(1982) EMBO J. 1, 1635—1640]. The C-terminal end is an integral part of the N-terminal domain. The consequences of the deletion of fifteen and three C-terminal amino acids on the conformational state and on the guanidine hydrochloride-induced and thermal unfolding of PGK were investigated by using near-and far-UV CD, tryptophan fluorescence, l-anilinonaphthalene-8-sulfonic acid binding, accessibility to chemicalmodification, and differential scanning calorimetry. The results of these studies indicate that the conformations of both domains and of the interdomain region were altered by these deletions. In the absence of the 15-amino acid C-terminal peptide [A (401—415)], the N-terminal domain exhibits several characteristics of a molten globule state, whereas the C-terminal domain retains native-like, although distinctly different, tertiary structure. Deletion of three C-terminal amino acids [A (413—415)] also globally affects PGK conformation, although to a much lesser extent. Both C-terminal deletions resulted in a significant decrease in protein stability, as demonstrated bytheir increased susceptibility to guanidine-induced and thermal denaturation. These results suggest that the formation of a native tertiary fold of PGK requires the presence of a complete polypeptide chain.PGK1 structure is composed of two domains with extensive domain—domain interactions. Each domain contains ap-proximately 200 amino acids, mostly corresponding to the N-and C-terminal halves of the amino acid sequence. The interdomain region includes N-and C-termini and a helix formed by the amino acids located in the middle of the amino acid sequence (Figure 1). Thus, the interdomain region in this protein contains segments of the polypeptide chain that are very distant in the unfolded state but become close in the folded conformation. The C-terminal end of the polypeptide chain constitutes an integral part of the N-terminal domain. This arrangement of the N-and C-termini suggests their important role in the folding of PGKdomains and their pairing during the folding process. Genetically engineered individual domains of yeast PGK have been isolated byYon and co-workers (Minard et al., 1989), who demonstrated that,
