Limited digestion of fructose 1,6-bisphosphatase with subtilisin produces an S-peptide with an about 60-residue peptide fragment that is non-covalently associated with the enzyme. The 60-residue peptide fragment con-s...Limited digestion of fructose 1,6-bisphosphatase with subtilisin produces an S-peptide with an about 60-residue peptide fragment that is non-covalently associated with the enzyme. The 60-residue peptide fragment con-sists of the most part of allosteric site for AMP binding. It could be separated from S-protein by gel filtration with a Sephadex G-75 column equilibrated with 9% formic acid. According to X-ray diffraction results the S-peptide consists of two α-helices without β-strand and the α-helix content is about 60% in the 60-residue-peptide fragment. When the enzyme is subjected to limited proteolysis with subtilisin, the secondary structure of the enzyme does not show a de-tectable change in CD spectrum. The CD spectra of the isolated S-peptide were measured under different concentra-tions. In the absence of GuHCl, S-peptide had 30% a-helix and 38.5% turn-like structure but had no β-strand, sug-gesting that the N-terminal 60-residue fragment, which is synthesized initially by ribosome, would展开更多
Although refolding of fully denatured protein molecules in vitro is not a valid model of folding of the nascent peptide chain in a biologically active protein in vivo, it can provide some useful information for protei...Although refolding of fully denatured protein molecules in vitro is not a valid model of folding of the nascent peptide chain in a biologically active protein in vivo, it can provide some useful information for protein folding. Therefore, refolding of denatured proteins has been extensively studied in recent years. It has been previously reported that during the refolding of guanidine or urea denatured creatine kinase, the enzymatic activity and the na-展开更多
基金Project supported in part by the National Natural Science Foundation of China and the Climbing Project of the State Science and Technology Commission of China.
文摘Limited digestion of fructose 1,6-bisphosphatase with subtilisin produces an S-peptide with an about 60-residue peptide fragment that is non-covalently associated with the enzyme. The 60-residue peptide fragment con-sists of the most part of allosteric site for AMP binding. It could be separated from S-protein by gel filtration with a Sephadex G-75 column equilibrated with 9% formic acid. According to X-ray diffraction results the S-peptide consists of two α-helices without β-strand and the α-helix content is about 60% in the 60-residue-peptide fragment. When the enzyme is subjected to limited proteolysis with subtilisin, the secondary structure of the enzyme does not show a de-tectable change in CD spectrum. The CD spectra of the isolated S-peptide were measured under different concentra-tions. In the absence of GuHCl, S-peptide had 30% a-helix and 38.5% turn-like structure but had no β-strand, sug-gesting that the N-terminal 60-residue fragment, which is synthesized initially by ribosome, would
文摘Although refolding of fully denatured protein molecules in vitro is not a valid model of folding of the nascent peptide chain in a biologically active protein in vivo, it can provide some useful information for protein folding. Therefore, refolding of denatured proteins has been extensively studied in recent years. It has been previously reported that during the refolding of guanidine or urea denatured creatine kinase, the enzymatic activity and the na-
