英语翻译PFA and other pyrococcal amylolytic enzymes.Koch et al.(24) described an extracellular a-amylase activity present in the supernatants of P.furiosus cultures.The activity they de¬scribed corresponded to two starch-degrading protein ba
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英语翻译PFA and other pyrococcal amylolytic enzymes.Koch et al.(24) described an extracellular a-amylase activity present in the supernatants of P.furiosus cultures.The activity they de¬scribed corresponded to two starch-degrading protein ba
英语翻译
PFA and other pyrococcal amylolytic enzymes.Koch et al.(24) described an extracellular a-amylase activity present in the supernatants of P.furiosus cultures.The activity they de¬scribed corresponded to two starch-degrading protein bands of 96 and 136 kDa in native PAGE.It is not clear from their work if these two bands correspond to one or two separate enzymes and if the 96-kDa band is similar to the enzyme described here.It is unlikely that these bands are the P.furiosus amylopullu-lanase (9,16),since no pullulanase activity was detected in their enzyme preparation (24).Another member of the order Thermococcales,T.profundus,optimally growing at 80°C,pro¬duced two extracellular amylases,S and L (12).With a molec¬ular mass of 42 kDa in SDS-PAGE,amylase S is optimally active at pH 5.5 to 6.0 and 80°C and does not require Ca2+ for its activity.While no sequence is available for amylase S,its catalytic properties suggest that it is the T.profundus counter¬part of PFA.Amylase L,a larger enzyme,could correspond to the P.furiosus 136-kDa amylolytic enzyme detected by Koch et al.(24).
A P.woesei extracellular a-amylase (PWA) has been purified and characterized by Koch et al.(23).PFA and PWA are optimally active under the same conditions of pH and temper¬ature and have similar resistance to thermal inactivation.Al¬though PWA was described as a 70,000-MW enzyme,as indi¬cated from migration in SDS-PAGE,it could correspond to a dimeric enzyme showing aberrant behavior under these elec-trophoresis conditions,a behavior similar to that observed with PFA.PFA and PWA seem to differ in two aspects:(i) PWA shows almost six-times-lower specific activity than PFA (667 versus 3,900 U mg_1),and (ii) their amino acid compositions seem to be different (in particular,PFA contains half the threonine residues present in PWA).P.furiosus and P.woesei amylopullulanases were also shown to be significantly different in a few aspects (16).Although these two organisms are con¬sidered to be very closely related,they still contain quite dif¬ferent enzymes.
PFA is the first archaeal amylolytic enzyme described that belongs to the a-amylase family.The characterization of ex¬tracellular a-amylases with similar properties from other hy-perthermophilic archaea (12,23) suggests that these enzymes also belong to the a-amylase family and that this enzyme family is widespread among the three kingdoms.
英语翻译PFA and other pyrococcal amylolytic enzymes.Koch et al.(24) described an extracellular a-amylase activity present in the supernatants of P.furiosus cultures.The activity they de¬scribed corresponded to two starch-degrading protein ba
粉煤灰和其他pyrococcal amylolytic酶.科克等.( 24 )描述了一个外1 -淀粉酶活性存在于上清体育球菌文化.他们的活动日¬抄相当于两个淀粉降解蛋白带96和136 kDa的本地页面.目前尚不清楚他们的工作,如果这两个频段对应的一个或两个独立的酶,如果96 - kDa的波段类似酶此处所述.这是不太可能,这些乐队是体育球菌amylopullu - lanase ( 9 ,16 ) ,因为没有普鲁兰酶的活性检测在其酶制剂( 24 ) .另一位成员为了Thermococcales ,吨深,最佳成长80 ℃ ,有利于两个¬诱导细胞外淀粉酶,硫和L ( 12 ) .随着分子¬血管数量的42 kDa的在SDS - PAGE分析,淀粉酶S是最活跃在pH 5.5 〜 6.0和80 ℃ ,并不需要钙离子的活动.虽然没有序列可用于淀粉硫,其催化性能研究表明,它是吨深反¬部分煤灰.淀粉酶L时,较大的酶,可以对应于体育球菌136 - kDa的amylolytic酶检测科克等.( 24 ) .
阿体育woesei外a一淀粉酶(巴勒斯坦供水局)已纯化和特点科克等.( 23 ) .煤灰和巴勒斯坦供水局的最佳活跃在相同条件下的pH值和脾气¬成熟和有类似的抗热灭活.铝¬尽管巴勒斯坦供水局被描述为7.0万兆瓦的酶,如个体¬ cated由移民在SDS - PAGE分析,它可以对应一个二聚体酶显示异常行为根据这些电泳条件下,这种行为类似于观察煤灰.煤灰和巴勒斯坦供水局似乎不同的两个方面:(一)巴勒斯坦供水局显示近6倍,具体的活动比降低煤灰( 667与3900 ü mg_1 ) ,和( ii )其氨基酸组成似乎是不同的(尤其是煤灰载有一半的苏氨酸残基在巴勒斯坦供水局) .体育球菌和P.woesei amylopullulanases也显示出显着不同的几个方面( 16 ) .尽管这两个生物体节能¬ sidered是非常密切相关,但它们仍然含有相当差¬不一样的酶.
粉煤灰是第一archaeal amylolytic酶属于描述的A -淀粉酶家族.定性前¬ tracellular 1 -淀粉酶具有类似特性的其他杂交perthermophilic古( 12 ,23 )表明,这些酶也属于一个家庭和淀粉酶,这种酶家族是普遍三国.
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英格兰和其他pyrococcal amylolytic酶。葛德华等。(二)描述的细胞活动中存在的a-amylase supernatants furiosus的文化。德修理他们的活动与两starch-degrading蛋白绘制的kDa当地并且136 96页。目前尚不清楚,从他们的工作如果这两个乐团对应一个或两个独立的酶,如果96-kDa乐队是相似的酶。这是不可能的,这些都是第furiosus am...
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英格兰和其他pyrococcal amylolytic酶。葛德华等。(二)描述的细胞活动中存在的a-amylase supernatants furiosus的文化。德修理他们的活动与两starch-degrading蛋白绘制的kDa当地并且136 96页。目前尚不清楚,从他们的工作如果这两个乐团对应一个或两个独立的酶,如果96-kDa乐队是相似的酶。这是不可能的,这些都是第furiosus amylopullu-lanase(9),因为没有pullulanase 16就是他们的酶活性准备(24)。另一成员的秩序,profundus Thermococcales增长趋势,80°C,duced个别细胞,和两amylases L(12)。有molec个别的42 kDa外阴在sds - page,淀粉酶活性,是优化pH 5.5到6.0和80°C,不需要为它的活动的钙。虽然没有提供,它为淀粉酶催化性能表明它是t profundus柜台的一部分。静脉PFA淀粉酶、更大的酵素,能与furiosus页136-kDa amylolytic葛检测酶等。(24)。
一页woesei a-amylase细胞(PWA)已经洁净了。并通过科赫等。(23)。英格兰和PWA最活跃的相同的条件下,ature脾气修理,pH值有相似的耐热失活。虽然PWA铝修理被描绘成70,000-MW酶、cated不可或缺的笔记本从移民,它能符合sds - page展示他的异常行为有dimeric酶,这些elec-trophoresis条件下的行为类似,观察和最佳。英格兰和PWA似乎在两个不同方面:(1)PWA几乎six-times-lower特定活动比PFA(667与3,900 U毫克1)、(2)他们的氨基酸组成似乎有所不同(特别是PFA包含一半的苏氨酸残留在PWA)。第furiosus和p . woesei amylopullulanases也显示出明显不同于几方面(16)。尽管这两种生物是欺诈类4非常密切相关,它们仍然含有相当不同酶进行修理。
第archaeal amylolytic时所描述的酶a-amylase家庭。事后的tracellular具有相似的性质a-amylases笔记本从其他hy-perthermophilic细菌(12,23)表明,这些酶也属于a-amylase家庭,这种酶的家庭是普遍存在的。
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