SPECIFICITY PROFILES OF MEMBRANE-BOUND GAMMA-D-GLUTAMYL-(L)MESO-DIAMINOPIMELATE ENDOPEPTIDASE AND LD-CARBOXYPEPTIDASE FROM BACILLUS-SPHAERICUS-9602
SPECIFICITY PROFILES OF MEMBRANE-BOUND GAMMA-D-GLUTAMYL-(L)MESO-DIAMINOPIMELATE ENDOPEPTIDASE AND LD-CARBOXYPEPTIDASE FROM BACILLUS-SPHAERICUS-9602
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DOI：
10.1111/j.1432-1033.1977.tb11351.x
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发表时间：
1977-01-01
期刊：
影响因子：
--
通讯作者：
MICHEL, G
中科院分区：
文献类型：
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作者：
ARMINJON, F;GUINAND, M;MICHEL, G
来自B的膜结合肽酶。Sphaericus 9602对各种肽进行测试，以确定每种酶的底物需求。LD-羧肽酶和γ-羧肽酶D-谷氨酰-内消旋-二氨基庚二酸内肽酶在相同底物上从不具有活性。LD-羧肽酶分裂含赖氨酸底物的L-Lys-D-Ala键和含msA 2pm底物的msA 2pm [内消旋-二氨基庚二酸]D-Ala键，所述底物在ω-氨基上具有酰胺基。羧基内肽酶水解。**图形 **。含有msA 2pm的肽和衍生物与游离ω- NH 2和ω- COOH基团。存在或不存在α-肽的第二个残基谷氨酸上的酰胺基对两种酶的特异性没有影响。同样，N-末端L-丙氨酸的N-取代不改变酶的特异性。动力学研究表明，MurNAc[N-乙酰胞壁酸] .**图形 **。和 **图形 **。是LD-羧肽酶的良好底物（表观Km分别为0.8 mM和1.25 mM）。.**图形 **。是内肽酶的最佳底物（表观Km = 0.33 mM）。谷氨酸上的酰胺基团使LD-羧肽酶和内肽酶活性降低80%。研究了内肽酶的各种抑制剂：DD-二氨基庚二酸和msA 2pm异构体是非常好的抑制剂。二羧酸D-氨基酸。**图形 **。也显示出作为侧链长度的函数的抑制作用：对于n = 4（D-α-D）观察到最大值。氨基庚二酸）。
Membrane-bound peptidases from B. sphaericus 9602 were tested upon various peptides to determine the substrate requirements of each enzyme. LD-Carboxypeptidase and .gamma.-D-glutamyl-meso-diaminopimelate endopeptidase were never active on the same substrate. LD-Carboxypeptidase splits the L-Lys-D-Ala linkage of lysine-containing substrates and the msA2pm[meso-diaminopimelic acid]D-Ala linkage of msA2pm-containing substrates which have an amide group on the .omega.-carboxyl. The endopeptidase hydrolyses the .**GRAPHIC**. linkage of msA2pm-containing peptides and derivatives with free .omega.-NH2 and .omega.-COOH groups. The presence or the absence of an .alpha.-amide group on glutamic acid, the 2nd residue of peptides, has no influence on the specificities of either enzyme. Likewise, N-substitution of N-terminal L-alanine does not modify the enzymic specificities. Kinetic studies showed that MurNAc[N-acetylmuramic acid] .**GRAPHIC**. and .**GRAPHIC**. are good substrates for LD-carboxypeptidase (apparent Km = 0.8 mM and 1.25 mM, respectively). .**GRAPHIC**. is the best substrate for the endopeptidase (apparent Km = 0.33 mM). An amide group on glutamic acid gives a decrease of 80% of LD-carboxypeptidase and endopeptidase activities. Various inhibitors of endopeptidase were studied: DD-diaminopimelic acid and msA2pm isomers are very good inhibitors. Dicarboxylic D-amino acids .**GRAPHIC**. also show an inhibition which is a function of the length of the side chain: the maximum is observed for n = 4 (D-.alpha.-aminopimelic acid).