Effects of the phenylalanine-22 .fwdarw. leucine, glutamic acid-49 .fwdarw. methionine, glycine-234 .fwdarw. aspartic acid and glycine-234 .fwdarw. lysine mutations on the folding and stability of the .alpha. subunit of tryptophan synthase from Escherichia coli [Erratum to document cited in CA104(23):203041c] | doi.page