Teppo A M, Maury C P
Scand J Immunol. 1983 Oct;18(4):363-6. doi: 10.1111/j.1365-3083.1983.tb01808.x.
Human serum contains enzyme(s) able to degrade serum amyloid A protein (SAA) and amyloid A (AA) fibrils. On the basis of inhibition tests these enzymes are regarded as serine proteases, but further characterization of the enzymes has, however, so far not been done. Chymotrypsin, trypsin, elastase, collagenase and kallikrein, when added to SAA-containing serum, all degraded SAA to peptides within 2 h at 37 degrees C. With the exception of collagenase these enzymes also destroyed the Sirius-Red-binding ability of amyloidotic tissue and that of isolated AA fibrils. Hence, they altered the conformation of the beta-pleated structure and possibly also degraded the fibrils. These results suggest that any of these serine proteases could be responsible of the degradation of SAA in serum. The enzyme concentrations needed to degrade amyloid fibrils, however, were much higher than normally found in serum. Thus, it is unlikely that the amyloid-fibril-degrading activity in serum could be due to any of these enzymes.
人血清中含有能够降解血清淀粉样蛋白A（SAA）和淀粉样蛋白A（AA）纤维的酶。基于抑制试验，这些酶被认为是丝氨酸蛋白酶，但到目前为止尚未对这些酶进行进一步的特性鉴定。当将胰凝乳蛋白酶、胰蛋白酶、弹性蛋白酶、胶原酶和激肽释放酶添加到含SAA的血清中时，在37℃下2小时内它们均将SAA降解为肽。除胶原酶外，这些酶还破坏了淀粉样变性组织和分离出的AA纤维与天狼星红的结合能力。因此，它们改变了β折叠结构的构象，并且可能还降解了纤维。这些结果表明，这些丝氨酸蛋白酶中的任何一种都可能是血清中SAA降解的原因。然而，降解淀粉样纤维所需的酶浓度远高于血清中通常发现的浓度。因此，血清中淀粉样纤维降解活性不太可能归因于这些酶中的任何一种。
