Abstract
We report a method to measure in vivo turnover of four proteins from sequential tracheal aspirates obtained from human newborn infants with respiratory distress syndrome using targeted proteomics. We detected enrichment for all targeted proteins approximately 3 h from the start of infusion of [5,5,5-(2)H(3)] leucine, secretion times that varied from 1.2 to 2.5 h, and half lives that ranged between 10 and 21 h. Complement factor B, a component of the alternative pathway of complement activation, had an approximately twofold-longer half-life than the other three proteins. In addition, the kinetics of mature and carboxy-terminal tryptic peptides from the same protein (surfactant protein B) were not statistically different (p = 0.49).
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Amino Acid Sequence
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Complement Factor B / analysis
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Complement Factor B / metabolism
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Humans
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Infant, Newborn
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Kinetics
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Mass Spectrometry / methods
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Molecular Sequence Data
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Protein Precursors / analysis
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Protein Precursors / metabolism
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Proteins / analysis*
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Proteins / metabolism*
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Proteolipids / analysis
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Proteolipids / metabolism
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Proteomics / methods*
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Pulmonary Surfactant-Associated Protein B / analysis
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Pulmonary Surfactant-Associated Protein B / metabolism
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Respiratory Distress Syndrome, Newborn / metabolism*
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Trachea / metabolism*
Substances
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Protein Precursors
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Proteins
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Proteolipids
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Pulmonary Surfactant-Associated Protein B
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surfactant protein B propeptide
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Complement Factor B