ArticleThe Biochemical journal2007
Structural and functional differences among human surfactant proteins SP-A1, SP-A2 and co-expressed SP-A1/SP-A2: role of supratrimeric oligomerization.
Article in The Biochemical journal, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 32 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
32 citing papers in PubMed, 53 citations in OpenAlex.
- Regulation of translation by upstream translation initiation codons of surfactant protein A1 splice variants.American journal of physiology. Lung cellular and molecular physiology · 2015Trial
- Surfactant protein A deficiency aggravates silica-induced pulmonary fibrosis by promoting intrinsic apoptosis of alveolar type II epithelial cells.Respiratory research · 2026Article
- The Immune Modulatory Role of Surfactants inJournal of inflammation research · 2025Review
- Anti-inflammatory and anti-viral actions of anionic pulmonary surfactant phospholipids.Biochimica et biophysica acta. Molecular and cell biology of lipids · 2022Review
- Cooperative action of SP-A and its trimeric recombinant fragment with polymyxins against Gram-negative respiratory bacteria.Frontiers in immunology · 2022Article
- The collectin SP-A and its trimeric recombinant fragment protect alveolar epithelial cells from the cytotoxic and proinflammatory effects of human cathelicidinFrontiers in immunology · 2022Article
- Signaling Pathways That Mediate Alveolar Macrophage Activation by Surfactant Protein A and IL-4.Frontiers in immunology · 2022Article
- Review
- Synergistic Action of Antimicrobial Lung Proteins againstInternational journal of molecular sciences · 2021Article
- Human Surfactant Protein SP-A1 and SP-A2 Variants Differentially Affect the Alveolar Microenvironment, Surfactant Structure, Regulation and Function of the Alveolar Macrophage, and Animal and Human Survival Under Various Conditions.Frontiers in immunology · 2021Review
- Recent progress on surfactant protein A: cellular function in lung and kidney disease development.American journal of physiology. Cell physiology · 2020Review
- Lipid-Protein and Protein-Protein Interactions in the Pulmonary Surfactant System and Their Role in Lung Homeostasis.International journal of molecular sciences · 2020Review
- Association of SNP-SNP Interactions of Surfactant Protein Genes with Pediatric Acute Respiratory Failure.Journal of clinical medicine · 2020Article
- SP-A and SP-D: Dual Functioning Immune Molecules With Antiviral and Immunomodulatory Properties.Frontiers in immunology · 2020Review
- Structural and Functional Determinants of Rodent and Human Surfactant Protein A: A Synthesis of Binding and Computational Data.Frontiers in immunology · 2019Article
- Ultrastructure of Highly Ordered Granules in Alveolar Type II Cells in Several Species.Anatomical record (Hoboken, N.J. : 2007) · 2018Article
- The Role of Collectins and Galectins in Lung Innate Immune Defense.Frontiers in immunology · 2018Review
- Genetic Association of Pulmonary Surfactant Protein Genes, SFTPA1, SFTPA2, SFTPB, SFTPC, and SFTPD With Cystic Fibrosis.Frontiers in immunology · 2018Article
- Local amplifiers of IL-4Rα-mediated macrophage activation promote repair in lung and liver.Science (New York, N.Y.) · 2017Article
- Novel expression of a functional trimeric fragment of human SP-A with efficacy in neutralisation of RSV.Immunobiology · 2017Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
SP-A (surfactant protein A) is a membrane-associated SP that helps to maintain the lung in a sterile and non-inflamed state. Unlike SP-As from other mammalian species, human SP-A consists of two functional gene products: SP-A1 and SP-A2. In all the functions examined, recombinant human SP-A1 invariably exhibits lower biological activity than SP-A2. The objective of the present study was to investigate why SP-A2 possesses greater biological activity than SP-A1 and what advantage accrues to having two polypeptide chains instead of one. We analysed structural and functional characteristics of recombinant baculovirus-derived SP-A1, SP-A2 and co-expressed SP-A1/SP-A2 using a wide array of experimental approaches such as analytical ultracentrifugation, DSC (differential scanning calorimetry) and fluorescence. We found that the extent of supratrimeric assembly is much lower in SP-A1 than SP-A2. However, the resistance to proteolysis is greater for SP-A1 than for SP-A2. Co-expressed SP-A1/SP-A2 had greater thermal stability than SP-A1 and SP-A2 and exhibited properties of each protein. On the one hand, SP-A1/SP-A2, like SP-A2, had a higher degree of oligomerization than SP-A1, and consequently had lower K(d) for binding to bacterial Re-LPS (rough lipopolysaccharide), higher self-association in the presence of calcium and greater capability to aggregate Re-LPS and phospholipids than SP-A1. On the other hand, SP-A1/SP-A2, like SP-A1, was more resistant to trypsin degradation than SP-A2. Finally, the importance of the supratrimeric assembly for SP-A immunomodulatory function is discussed.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.