Pałka J A
Rocz Akad Med Bialymst. 1996;41(2):149-60.
Prolidase (E.C. 3.4.13.9) is a cytosolic exopeptidase that cleaves imidodipeptides and imidotripeptides with C-terminal proline or hydroxyproline. The enzyme apparently contributes to the conservation of iminoacids from endogenous and exogenous protein sources, mainly collagen. Prolidase plays an important role in the recycling of proline for collagen synthesis and cell growth and probably serves as an interface between protein nutrition and matrix breakdown. It seems that prolidase activity (despite the collagen gene expression) may be a step limiting factor in the regulation of collagen biosynthesis. The prolidase gene (PEPD) is located on chromosome 19 and encodes a polypeptide of 493 amino acids with molecular weight 54 kDa. The mature form of the enzyme is a dimer composed of two identical subunits. The gene harbors polymorphic alleles without effect on activity. Rare mutations found on exons 7,8,12 and 14 may be responsible for prolidase deficiency. Prolidase deficiency is characterized by massive imidodipeptiduria, skin lesions, recurrent infections, mental retardation and elevated proline-containing dipeptides in plasma. An effective treatment of the disease has not been identified.
脯氨酰二肽酶（E.C. 3.4.13.9）是一种胞质外肽酶，可切割C端为脯氨酸或羟脯氨酸的亚氨基二肽和亚氨基三肽。该酶显然有助于从内源性和外源性蛋白质来源（主要是胶原蛋白）中保存亚氨基酸。脯氨酰二肽酶在脯氨酸循环以进行胶原蛋白合成和细胞生长过程中发挥重要作用，并且可能充当蛋白质营养与基质分解之间的接口。脯氨酰二肽酶活性（尽管有胶原蛋白基因表达）似乎可能是胶原蛋白生物合成调节中的一个限速步骤。脯氨酰二肽酶基因（PEPD）位于19号染色体上，编码一个由493个氨基酸组成、分子量为54 kDa的多肽。该酶的成熟形式是由两个相同亚基组成的二聚体。该基因含有对活性无影响的多态性等位基因。在外显子7、8、12和14上发现的罕见突变可能是脯氨酰二肽酶缺乏症的病因。脯氨酰二肽酶缺乏症的特征是大量亚氨基二肽尿、皮肤病变、反复感染、智力迟钝以及血浆中含脯氨酸的二肽升高。尚未确定该疾病的有效治疗方法。
