Sugahara K, Schwartz N B
Proc Natl Acad Sci U S A. 1979 Dec;76(12):6615-8. doi: 10.1073/pnas.76.12.6615.
Incorporation of 35SO42- into adenosine 5'-phosphosulfate (APS), 3'-phosphoadenosine 5'-phosphosulfate (PAPS), and chondroitin sulfate was simultaneously assessed with extracts prepared from epiphyseal cartilage of neonatal normal or homozygous brachymorphic mice. Radioactivity measured in APS, PAPS, and chondroitin sulfate of extracts from brachymorphic cartilage was approximately 300%, 9%, and 13% of the normal levels, respectively. Even though more APS accumulated in the mutant cartilage extracts, APS actually synthesized (total 35SO42- incorporated into APS, PAPS, and macromolecular products) was only 17% of that in the normal. However, of the amount synthesized, 90% and 55% of newly synthesized APS were converted to PAPS by cartilage extracts of normal and brachymorphic mice, respectively. Specific assays for ATP sulfurylase (sulfate adenylyltransferase; ATP:sulfate adenylyltransferase, EC 2.7.7.4) and APS kinase (adenylylsulfate kinase; ATP:adenylylsulfate 3'-phosphotransferase, EC 2.7.1.25) showed that the sulfurylase enzyme activity is reduced to approximately 1/2 and the kinase to approxomately 1/14 in brachymorphic mice. These results suggest that the production of an undersulfated proteoglycan in brachymorphic cartilage results from a defective conversion of APS to PAPS.
采用从新生正常小鼠或纯合短肢小鼠的骨骺软骨制备的提取物，同时评估了35SO42-掺入腺苷5'-磷酸硫酸酯（APS）、3'-磷酸腺苷5'-磷酸硫酸酯（PAPS）和硫酸软骨素的情况。短肢软骨提取物中APS、PAPS和硫酸软骨素的放射性测量值分别约为正常水平的300%、9%和13%。尽管突变软骨提取物中积累了更多的APS，但实际合成的APS（掺入APS、PAPS和大分子产物中的总35SO42-）仅为正常水平的17%。然而，在合成量中，正常小鼠和短肢小鼠的软骨提取物分别将新合成的APS的90%和55%转化为PAPS。对ATP硫酸化酶（硫酸腺苷酰转移酶；ATP：硫酸腺苷酰转移酶，EC 2.7.7.4）和APS激酶（腺苷酰硫酸激酶；ATP：腺苷酰硫酸3'-磷酸转移酶，EC 2.7.1.25）的特异性测定表明，短肢小鼠中硫酸化酶的酶活性降低至约1/2，激酶降低至约1/14。这些结果表明，短肢软骨中硫酸化不足的蛋白聚糖的产生是由于APS向PAPS的转化存在缺陷。
