Reynolds D S, Gurley D S, Stevens R L, Sugarbaker D J, Austen K F, Serafin W E
Department of Medicine, Harvard Medical School, Boston, MA.
Proc Natl Acad Sci U S A. 1989 Dec;86(23):9480-4. doi: 10.1073/pnas.86.23.9480.
Human skin and lung mast cells and rodent peritoneal mast cells contain a carboxypeptidase in their secretory granules. We have screened human lung cDNA libraries with a mouse mast cell carboxypeptidase A (MC-CPA) cDNA probe to isolate a near-full-length cDNA that encodes human MC-CPA. The 5' end of the human MC-CPA transcript was defined by direct mRNA sequencing and by isolation and partial sequencing of the human MC-CPA gene. Human MC-CPA is predicted to be translated as a 417 amino acid preproenzyme which includes a 15 amino acid signal peptide and a 94 amino acid activation peptide. The mature human MC-CPA enzyme has a predicted size of 36.1 kDa, a net positive charge of 16 at neutral pH, and 86% amino acid sequence identity with mouse MC-CPA. DNA blot analyses showed that human MC-CPA mRNA is transcribed from a single locus in the human genome. Comparison of the human MC-CPA with mouse MC-CPA and with three rat pancreatic carboxypeptidases shows that these enzymes are encoded by distinct but homologous genes.
人类皮肤和肺部的肥大细胞以及啮齿动物腹膜肥大细胞在其分泌颗粒中含有一种羧肽酶。我们用小鼠肥大细胞羧肽酶A（MC-CPA）cDNA探针筛选人类肺cDNA文库，以分离出编码人类MC-CPA的近全长cDNA。通过直接mRNA测序以及人类MC-CPA基因的分离和部分测序确定了人类MC-CPA转录本的5'端。预计人类MC-CPA被翻译为一种417个氨基酸的前体酶原，其中包括一个15个氨基酸的信号肽和一个94个氨基酸的激活肽。成熟的人类MC-CPA酶预计大小为36.1 kDa，在中性pH下净正电荷为16，与小鼠MC-CPA的氨基酸序列同一性为86%。DNA印迹分析表明，人类MC-CPA mRNA是从人类基因组中的一个位点转录而来的。将人类MC-CPA与小鼠MC-CPA以及三种大鼠胰腺羧肽酶进行比较表明，这些酶由不同但同源的基因编码。
