Abstract
We previously reported that a human analogue of pulmonary surfactant protein-C (SP-C), SP-CL16 (6—28), with 23 residues was the most active analogue in a reconstituted lipid mixture and had the shortest chain among the poly leucine analogues examined.
In this study, we verified the influence of albumin, a component of serum, on the surface activity of surfactant. Surface activity was measured using the Langmuir–Wilhelmy surface balance (WSB), pulsating bubble surfactometer (PBS), and stable microbubble test (MBT). The surface activity of synthetic lung surfactant (SLS) was only slightly influenced by albumin (0.1—10 mg/ml) as compared with that of a ternary mixture of phospholipids. The ternary mixture of phospholipids showed a decrease in surface activity due to albumin. In particular, SLS did not show interaction of surface activity with albumin in vitro (WSB, PBS, and MBT). In contrast, dipalmitoylphosphatidylcholine/phosphatidylglycerol/palmitic acid had significantly weaker surface activity in the presence of albumin. Surfactant-TA showed interaction of surface activity with albumin in the MBT. The number of stable microbubble increased in the presence of albumin at a concentration of 0.1 mg/ml.
