Saccharification of β-chitin from squid pen by a fermentation method using recombinant chitinase-secreting Escherichia coli.

Two strains [BL21(DE3) and HMS174(DE3)] of Escherichia coli harboring the recombinant chitinase expression plasmid pVP-Chi, which contains Vibrio parahaemolyticus chitinase gene with an attached signal sequence, were prepared. These E. coli transformants produced a large amount of recombinant chitinase, which hydrolyzes chitin to yield di-N-acetylchitobiose (GlcNAc)2, under the presence of isopropyl-1-thio-β-D-galactopyranoside (IPTG), and secreted the enzyme into their culture fluid with the aid of the signal peptide.

Expansion of the first polyalanine tract of the ARX gene in a boy presenting with generalized dystonia in the absence of infantile spasms.

Mutations in the Aristaless-related homeobox (ARX) gene are associated with pleiotropic phenotypes including infantile spasms, mental retardation and dystonia. However, relatively consistent genotype-phenotype correlations have been emphasized in prior reports. We report a boy presenting with mental retardation, tonic seizures and dystonia but without infantile spasms.