[Characteristics of the complex formation of L-DOPA with chromatin elements from brain cells]

It was found that L-DOPA interacts with brain cell chromatin. The life-time of the chromatin-L-DOPA complex is the greatest at 24 degrees C, while at 37 degrees C the destruction of the complex is observed. The specific binding is about 40% at pH 7.4-7.6. The Kd value calculated by the method of Scatchard is equal to 35.10(-9) M. Treatment of the chromatin-L-DOPA complex with DNAase I decreases the chromatin radioactivity by 15-20%. At the same time pronase treatment decreases the chromatin radioactivity by 80%. NaCl (0.2 and 0.4 M) causes the extraction of more than 70% of 3H-DOPA in the complex with chromatin proteins. Thus, L-DOPA interacts predominantly with chromatin proteins.