This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Flach, C. R. Articles by Mendelsohn, R. Search for Related Content PubMed PubMed Citation Articles by Flach, C. R. Articles by Mendelsohn, R.

Location of Structural Transitions in an Isotopically Labeled Lung Surfactant SP-B Peptide by IRRAS

Carol R. Flach ^*, Peng Cai ^*, Darline Dieudonné ^*, Joseph W. Brauner ^*, Kevin M. W. Keough , June Stewart  and Richard Mendelsohn ^*

^*Department of Chemistry, Newark College of Arts and Sciences, Rutgers University, Newark, New Jersey USA; and Department of Biochemistry, Memorial University of Newfoundland, St. John's, Canada

Correspondence: Address reprint requests to Carol R. Flach, Dept. of Chemistry, Rutgers University, 73 Warren St., Newark, NJ 07102. Tel.: 973-353-1330; Fax: 973-353-1264; E-mail: flach{at}andromeda.rutgers.edu.

Pulmonary surfactant, a lipid/protein complex that lines the air/water interface in the mammalian lung, functions to reduce the work of breathing. Surfactant protein B (SP-B) is a small, hydrophobic protein that is an essential component of this mixture. Structure-function relationships of SP-B are currently under investigation as the protein and its peptide analogs are being incorporated into surfactant replacement therapies. Knowledge of the structure of SP-B and its related peptides in bulk and monolayer phases will facilitate the design of later generation therapeutic agents. Prior infrared reflection-absorption spectroscopic studies reported notable, reversible surface pressure-induced antiparallel ß-sheet formation in a synthetic peptide derived from human SP-B, residues 9–36 (SP-B_9–36). In the current work, infrared reflection-absorption spectroscopy is applied in conjunction with isotopic labeling to detect the site and pressure dependence of the conformational change. SP-B_9–36, synthesized with ¹³C=O-labeled Ala residues in positions 26, 28, 30, and 32, shifted the ß-sheet marker band to 1600 cm^-1 and thus immediately identified this structural element within the labeled region. Surface pressure-induced alterations in the relative intensities of Amide I band constituents are interpreted using a semiempirical transition dipole coupling model. In addition, electron micrographs reveal the formation of tubular myelin structures from in vitro preparations using SP-B_9–36 in place of porcine SP-B indicating that the peptide has the potential to mimic this property of the native protein.

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]