Sequence of human carboxypeptidase D reveals it to be a member of the regulatory carboxypeptidase family with three tandem active site domains.
Sequence of human carboxypeptidase D reveals it to be a member of the regulatory carboxypeptidase family with three tandem active site domains.
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人羧肽酶 D 的序列表明它是具有三个串联活性位点结构域的调节性羧肽酶家族的成员。
DOI：
10.1042/bj3270081
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Skidgel,RA
中科院分区：
文献类型：
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作者：
Tan,F;Rehli,M;Krause,SW;Skidgel,RA
我们克隆了人羧肽酶D（CPD）的cDNA，CPD是一种新的B型羧肽酶，它是膜结合的，具有酸性pH最适。该cDNA全长5.8 kb，开放阅读框为4131 bp，编码1377个氨基酸残基。该序列与鸭gp 180相似（75%同一性），鸭gp 180是一种分离、克隆和测序的B型肝炎病毒结合蛋白，但不具有羧肽酶的特征。亲水性分析揭示了在N-末端的疏水区域，代表信号肽，和一个接近C-末端，可能代表跨膜锚。最显著的特征是存在三个串联羧肽酶同源结构域，其与以羧肽酶M、E和N为代表的调节性B型羧肽酶家族具有序列相似性。由于三个重复序列，CPD比该家族的其他成员大约三倍（175-180 kDa）（约100 kDa）。50-62 kDa）。结构域2与羧肽酶M、E和N最密切相关（45-48%同一性），其次是结构域1（37-38%）和结构域3（20-27%）。在含有推定的活性位点残基的区域中存在高得多的序列同一性，并且所有催化重要的残基在结构域1和2中严格保守。然而，在结构域3中，8个活性位点残基中只有1个是保守的，表明该部分可能没有催化活性。北方印迹显示CPD mRNA在胎盘、胰腺和Hep G2肝癌细胞中表达量较高，在骨骼肌、心脏、HT-29结肠癌和黑色素瘤细胞系中表达量较低。
We have cloned the cDNA for human carboxypeptidase D (CPD), a new B-type metallocarboxypeptidase that is membrane bound and has an acidic pH optimum. The 5.8 kb of cDNA sequenced contains an open reading frame of 4131 bp encoding 1377 amino acid residues. The sequence is similar (75% identity) to duck gp180, a protein that was isolated, cloned and sequenced as a hepatitis B virus-binding protein but not characterized as a carboxypeptidase. Hydropathic analysis revealed a hydrophobic region at the N-terminus, representing the signal peptide, and one near the C-terminus that probably represents the transmembrane anchor. The most striking feature is the presence of three tandem carboxypeptidase homology domains that have sequence similarity to the regulatory B-type carboxypeptidase family, typified by carboxypeptidases M, E and N. Because of the three repeats, CPD is about three times larger (175–180 kDa) than other members of this family (approx. 50–62 kDa). Domain 2 is most closely related to carboxypeptidases M, E and N (45–48% identity), followed by domain 1 (37–38%) and domain 3 (20–27%). There is much higher sequence identity in regions containing putative active site residues, and all catalytically important residues are strictly conserved in domains 1 and 2. In domain 3, however, only 1 of 8 active site residues is conserved, indicating that this portion might not be catalytically active. Northern blotting of mRNA from human tissues and cells showed high levels of CPD mRNA in placenta, pancreas and Hep G2 hepatoma cells, and smaller amounts in skeletal muscle, heart and HT-29 colon carcinoma and melanoma cell lines.