Bosmann H B, Case K R
Neurobiology. 1975 Mar;5(1):35-41.
Rat cerebral cortex neuronal nuclei were isolated by a mild technique utilizing sucrose; citric acid was not used in the isolation of the nuclei. These nuclei in 0.0145 M NaC1, 4.5 per cent sorbitol, and 0.6 mM NaHCO3 with pH 7.2 plus or minus 0.1 at 25 degrees C had an electrophoretic morbidity of minus 2.01 mum-s(-1)-V(-1)-cm(-1). The mobility curves for the brain nuclei indicated that the surface had an acid-dissociable group of pK APPROXIMATELY 2.7. Nuclei treated with 50 mg neurominidase/mg particle protein had a mobility of minus 1.4 mum-s(-1)-V(-1)-cm(-1). DNase or RNase at 50 mug/mg protein had no effect on the mobility of the isolated nuclei. Concanavalin A at 50 mug/mg protein decreased the nuclei electrophoretic mobility to minus 1.82 mum-s(-1)-V(-1)-cm(-1). The results are interpreted to mean that the brain nuclear external surface contains terminal sialic acid residues, but it is completely devoid of nucleic acids, and it binds canavalin A.
采用一种使用蔗糖的温和技术分离大鼠大脑皮质神经元细胞核;分离细胞核时未使用柠檬酸。这些细胞核在0.0145M氯化钠、4.5%山梨醇和0.6mM碳酸氢钠中,于25℃时pH为7.2±0.1,其电泳迁移率为-2.01μm·s⁻¹·V⁻¹·cm⁻¹。脑细胞核的迁移率曲线表明,其表面有一个pK约为2.7的酸可解离基团。用50mg神经氨酸酶/mg颗粒蛋白处理的细胞核迁移率为-1.4μm·s⁻¹·V⁻¹·cm⁻¹。50μg/mg蛋白的脱氧核糖核酸酶或核糖核酸酶对分离细胞核的迁移率无影响。50μg/mg蛋白的伴刀豆球蛋白A使细胞核电泳迁移率降至-1.82μm·s⁻¹·V⁻¹·cm⁻¹。结果被解释为意味着脑细胞核外表面含有末端唾液酸残基,但完全不含核酸,且能结合伴刀豆球蛋白A。