Ng T B, Ng A S, Wong C C
Department of Biochemistry, Faculty of Medicine, Chinese University Hong Kong, Shatin, New Territories.
Biochem Int. 1990;20(6):1111-8.
Snake (Ptyas mucosa) pituitaries were heated, extracted with an acidic medium, and the extract subsequently chromatographed on carboxymethyl cellulose (CMC). Fractions were assayed for their abilities to displace D-ala2-D-leu5-[tyrosyl, 3,53H] enkephalin from binding to rat brain membranes and 125I-beta-endorphin from binding to its antibody, and to stimulate corticosterone production by isolated rat adrenal cells. The fraction unadsorbed on CMC (having the least basic character) had the lowest opiate receptor binding activity and beta-endorphin-like immunoreactivity. The highest steroidogenic activity, opiate receptor binding activity and beta-endorphin-like immunoreactivity were concentrated in a strongly adsorbed fraction. Snake pituitaries were also extracted with Tris-HCl buffer (pH 7.8). The extract from the second procedure was subsequently chromatographed on ConA-Sepharose, ultrafiltered and dialyzed to obtain a nonglycopeptide fraction with a molecular weight between 1,000 and 10,000. This fraction also exhibited steroidogenic and opiate receptor binding activities.
将蛇（滑鼠蛇）的脑垂体加热，用酸性介质提取，提取物随后在羧甲基纤维素（CMC）上进行色谱分析。对各馏分进行检测，以评估它们从与大鼠脑膜的结合中置换D-ala2-D-leu5-[酪氨酸，3,5-3H]脑啡肽以及从与β-内啡肽抗体的结合中置换125I-β-内啡肽的能力，以及刺激分离的大鼠肾上腺细胞产生皮质酮的能力。未吸附在CMC上的馏分（碱性最弱）具有最低的阿片受体结合活性和β-内啡肽样免疫反应性。最高的类固醇生成活性、阿片受体结合活性和β-内啡肽样免疫反应性集中在一个强烈吸附的馏分中。蛇脑垂体也用Tris-HCl缓冲液（pH 7.8）提取。随后将第二步提取的提取物在伴刀豆球蛋白A-琼脂糖上进行色谱分析，超滤并透析，以获得分子量在1000至10000之间的非糖肽馏分。该馏分也表现出类固醇生成和阿片受体结合活性。
