ABSTRACT
Most of pigments were made of aromatics extracted from cola tar. As early as 1895, aromatics were found to be carcinogenic. In 1974, ETAD had tested 50 more kinds of aromatics and found that 22 had carcinogenic role. In 1994, Germany revised the law of articles of everyday use and clearly stipulated that aromatics were prohibited to be used in production of cloth dye. Bayer had prohibited the use of 118 kinds of pigments such as aromatics, etc. In 1997, the number of prohibited pigments rose to 141. The AATCC in America plans to use environment-protecting pigments instead of aromatic pigments. In order to keep the status of great power in export textile, India had prohibited the use of 116 kinds of pigments and built a monitoring center.Internationally, the trader should show the customer a booklet of instructions indicating that the cloth does not have any pigments, which may be carcinogenic, allergenic or have hormone disrupting characteristics.
ABSTRACT
AIM: To construct a high-level expression system of recombinant human neuronal nitric oxide synthase (hnNOS) full-length enzyme in Escherichia coli. METHODS: The coding sequence of hnNOS full-length was firstly amplified by PCR, and then ligated into the expression vector pCWori+. The recombinant plasmid was transformed into Escherichia coli BL21 for high-level expression. After having been checked with Western blot, the enzyme was used for large-scale culture and purification. Finally, the property of the enzyme was determined by spectrophotometric method. RESULTS: The constructed expression system could give a yielding of 3 mg/L initial culture. CONCLUSION: The expression system constructed is fully sufficient to express the active human neuronal nitric oxide synthase.