| Surfactant Protein SP-A, B, and C: Purification and Biochemical Characterization |
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Chong-Woo Bae1, Yong-Mook Choi1, Joo Hyun Kang2, Kil Lyong Kim2, Kyung Soo Hahn2 |
1Department of Pediatrics, College of Medicine, Kyunghee University, Seoul, Korea
2Korea Research Institute of Bioscience and Biotechnology, KIST, Taejon, Korea |
| Pulmonary Surfactant Protein SP-A, B, C의 분리 제조 및 생화학적 특성에 관한 연구 |
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배종우1, 최용묵1, 강주현2, 김길룡2, 함경수2 |
1경희대학교 의과대학 소아과학교실
2한국과학기술연구원 생명공학연구소 |
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| Abstract |
Purpose
: Several kinds of exogenous pulmonary surfactants (SF), either synthetic or animalderived,
are being used for the replacement therapy in respiratory distress syndrome (RDS) of
newborn, especially in premature infants, and improved the neonatal mortality and morbidity.
Because synthetic preparations are lack of surfactant protein (SP) and animal-derived
preparations cause immunogenecity of heterogenous SP, there have been great necessity for the
development of next generation of exogenous SF which made by new technology to produce
new type of human SF (contained human synthetic SP). There are two methods to make next
generation of SF (mixtures of phospholipids and human synthetic SP) which are using of
recombinant SP or synthetic peptides of SP. For the synthesis of SP peptides and production of
next generation of SF, at first step, we have isolated SP-A, B, and C from bovine lung SF,
and studied the biochemical properties of these proteins.
Methods
: Crude natural surfactant (CNS) and purified natural surfactant (PNS) were isolated
from materials which extracted from the bovine lung lavage. The hydrophilic SP-A was purified
from PNS by method of modified Hawgood, and hydrophobic SP-B, C were purified by
Sephadex LH 60 column chromatography. The purities of the purified SP-A and SP-B, C were
assessed by 12% SDS-polyacrylamide gel and tricine buffer SDS-polyacrylamide gel, respectively
and the N-terminal amino acid sequences of these proteins were determined using Beckman
PI-2090. The polyclonal anti-serum against SP-A was prepared by immunization of the purified
SP-A into the mouse and the immunization of the purified SP-A into the mouse and the
immunogenecity of SP-A was confirmed by indirect ELISA.
Results
: Total 22 gm of CNS, 11 gm of PNS, and 2.5 mg of SP-B and 3.2 mg of SP-C/ 1 gm
of CNS, were purified from one bovine both lungs. The molecular weights of SP-A, B, C shown
in SDS-polyacrylamide gel were as follows; 28,000-35,000 Da (molecular weight) of SP-A,
15,000-18,000 Da of SP-B, 3,500-5,000 Da of SP-C. The partial N-terminal amino acid sequences
of each SPs were; Leu-Glu-His-Asp-Val-Lys- Glu-Val-¡¤¡¤¡¤¡¤ in SP-A, Phe-Pro-Ile-Pro-Ile-Pro-Tyr-¡¤¡¤¡¤¡¤
in SP-B, Leu-Ile-Pro-¡¤¡¤¡¤¡¤ in SP-C, respectively. These results indicated that the amino acid sequences
of bovine SPs were different from those of other species, i.e., human, dog and rat, which were
reported previously by another investigators and species-specific patterns were shown. The
immunogenecity of the purified SP-A was confirmed by the production of polyclonal antibody
against mouse. The polyclonal antibody of SP-A could be used for measuring the amount of
pulmonary SF in lung lavages. Carbohydrate portion of SP-A was cleaved with N-glycocisidase F.
This result suggested that carbohydrate group could be N-glycosylated in some arginine residue of
SP-A.
Conclusion
: The SP-A, B, C were purified from bovine lung SF, and N-terminal amino acid
sequences of each SP-A, B, C were determined. Further studies were needed for the
development and use of next generations of exogenous SF preparation, which based on synthetic
SP-peptides, for the treatment of neonatal RDS in the future. |
| Key Words:
Pulmonary surfactant, Surfactant protein (SP), SP-A, B, C, Peptides, Amino acid seguence, Respiratory distress syndrome (RDS) in newborn infants |
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