Biophys J, July 2000, p. 377-384, Vol. 79, No. 1

Dimeric N-Terminal Segment of Human Surfactant Protein B (dSP-B_1-25) Has Enhanced Surface Properties Compared to Monomeric SP-B_1-25

Edwin J. A. Veldhuizen,^* Alan J. Waring, Frans J. Walther, Joseph J. Batenburg,^* Lambert M. G. van Golde,^* and Henk P. Haagsman^*

 ^*Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, the Netherlands;  Department of Pediatrics, Charles Drew University, Los Angeles, California 90059, and Perinatal Research Laboratories, Harbor-UCLA Research and Education Institute, Torrance, California 90502 USA; and  Department of Science of Food of Animal Origin, Utrecht University, 3508 TD, Utrecht, the Netherlands

Surfactant protein B (SP-B) is a 17-kDa dimeric protein produced by alveolar type II cells. Its main function is to lower the surface tension by inserting lipids into the air/liquid interface of the lung. SP-B's function can be mimicked by a 25-amino acid peptide, SP-B_1-25, which is based on the N-terminal sequence of SP-B. We synthesized a dimeric version of this peptide, dSP-B_1-25, and the two peptides were tested for their surface activity. Both SP-B_1-25 and dSP-B_1-25 showed good lipid mixing and adsorption activities. The dimeric peptide showed activity comparable to that of native SP-B in the pressure-driven captive bubble surfactometer. Spread surface films led to stable near-zero minimum surface tensions during cycling while protein free, and films containing SP-B_1-25 lost material from the interface during compression. We propose that dimerization of the peptide is required to create a lipid reservoir attached to the monolayer from which new material can enter the surface film upon expansion of the air/liquid interface. The dimeric state of SP-B can fulfill the same function in vivo.

Biophys J, July 2000, p. 377-384, Vol. 79, No. 1
© 2000 by the Biophysical Society   0006-3495/00/07/377/08  $2.00

This article has been cited by other articles:

				A. G. Serrano, M. Ryan, T. E. Weaver, and J. Perez-Gil Critical Structure-Function Determinants within the N-Terminal Region of Pulmonary Surfactant Protein SP-B Biophys. J., January 1, 2006; 90(1): 238 - 249. [Abstract] [Full Text] [PDF]

				Z. Wang, A. L. Schwan, L. L. Lairson, J. S. O'Donnell, G. F. Byrne, A. Foye, B. A. Holm, and R. H. Notter Surface activity of a synthetic lung surfactant containing a phospholipase-resistant phosphonolipid analog of dipalmitoyl phosphatidylcholine Am J Physiol Lung Cell Mol Physiol, September 1, 2003; 285(3): L550 - L559. [Abstract] [Full Text] [PDF]

				C. R. Flach, P. Cai, D. Dieudonne, J. W. Brauner, K. M. W. Keough, J. Stewart, and R. Mendelsohn Location of Structural Transitions in an Isotopically Labeled Lung Surfactant SP-B Peptide by IRRAS Biophys. J., July 1, 2003; 85(1): 340 - 349. [Abstract] [Full Text] [PDF]

				M. Ikegami, N. Takabatake, and T. E. Weaver Intersubunit disulfide bridge is not required for the protective role of SP-B against lung inflammation J Appl Physiol, August 1, 2002; 93(2): 505 - 511. [Abstract] [Full Text] [PDF]

				R. V. Diemel, M. M. E. Snel, A. J. Waring, F. J. Walther, L. M. G. van Golde, G. Putz, H. P. Haagsman, and J. J. Batenburg Multilayer Formation upon Compression of Surfactant Monolayers Depends on Protein Concentration as Well as Lipid Composition. AN ATOMIC FORCE MICROSCOPY STUDY J. Biol. Chem., June 7, 2002; 277(24): 21179 - 21188. [Abstract] [Full Text] [PDF]

				K. Rodriguez-Capote, K. Nag, S. Schurch, and F. Possmayer Surfactant protein interactions with neutral and acidic phospholipid films Am J Physiol Lung Cell Mol Physiol, July 1, 2001; 281(1): L231 - L242. [Abstract] [Full Text] [PDF]