This is a pre- or post-print of an article published in Chen, H.-L., Lünsdorf, H., Hecht, H.-J., Tsai, H. Porcine pulmonary angiotensin I-converting enzyme-Biochemical characterization and spatial arrangement of the N- and C-domains by three- dimensional electron microscopic reconstruction (2010) Micron, 41 (6), pp. 674-685.