CONVERSION OF ACTIVE-SITE CYSTEINE RESIDUE OF PAPAIN INTO A DEHYDRO-SERINE, A SERINE AND A GLYCINE RESIDUE
CONVERSION OF ACTIVE-SITE CYSTEINE RESIDUE OF PAPAIN INTO A DEHYDRO-SERINE, A SERINE AND A GLYCINE RESIDUE
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DOI：
10.1111/j.1432-1033.1978.tb12168.x
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发表时间：
1978-01-01
期刊：
影响因子：
--
通讯作者：
LOWE, G
中科院分区：
文献类型：
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作者：
CLARK, PI;LOWE, G
被2-溴-2‘’，4‘-二甲氧基苯乙酮抑制的木瓜酶[木瓜胶乳]的光解再生木瓜酶，但也通过中间体脱氢半胱氨酸类似物[ΔCys25]-木瓜酶生成[ΔSer25]木瓜酶(即，其中活性部位的半胱氨酸残基25被脱氢丝氨酸取代的木瓜酶)。用硼氢化钠还原得到[Ser25]木瓜酶。[Ser25]木瓜酶和[DELTA Ser25]-木瓜酶都具有与木瓜酶相似的结合性质，但没有酶活性。研究了它们的荧光性质。[Gly25]木瓜酶在pH 9.0下孵育得到[Gly25]木瓜酶。
Photolysis of papain [papaya latex] which was inhibited with 2-bromo-2'',4''-dimethoxyacetophenone regenerated papain, but also formed [.DELTA.Ser25]papain (i.e., papain in which the active-site cysteine residue 25 was replaced by dehydroserine) via the intermediate dehydrocysteine analog, [.DELTA.Cys25]-papain. Reduction with sodium borohydride gave [Ser25]papain. Both [Ser25]papain and [.DELTA.Ser25]-papain had binding properties similar to those of papain, but were devoid of enzymic activity. Their fluorescence properties were also investigated. Incubation of [.DELTA.Ser25]papain at pH 9.0 gave [Gly25]papain.