Molecular basis of alpha-1-antitrypsin deficiency. Review uri icon

Overview

MeSH

  • Alleles
  • Gene Expression Regulation
  • Humans
  • Liver Diseases
  • Pulmonary Emphysema
  • alpha 1-Antitrypsin

MeSH Major

  • alpha 1-Antitrypsin Deficiency

abstract

  • Alpha-1-antitrypsin (A1AT) deficiency is an autosomal hereditary disorder associated with a major reduction in serum A1AT levels. Clinically, A1AT deficiency is associated with emphysema in adults and, less commonly, liver disease in neonates. A1AT is a 52-kDa, 394-amino acid, single-chain glycoprotein normally present in serum at 150 to 350 mg/dl. The A1AT gene, composed of seven exons dispersed over 12 kb of chromosomal segment 14q31-32.3, is expressed in hepatocytes and mononuclear phagocytes. The A1AT protein, a member of the class of protease inhibitor proteins known as serpins (serine protease inhibitors), is a globular molecule composed of nine alpha-helices and three beta-pleated sheets. The major function of A1AT is to inhibit neutrophil elastase; A1AT does so through an active site centered around Met358 contained within an external stressed loop on the surface of the molecule. A1AT is a highly pleomorphic protein with greater than 75 variants determined at the protein and/or gene level. These variants can be categorized into four groups according to their serum A1AT level and function: normal, deficient, dysfunctional, and absent. There are two important salt bridges within the A1AT molecule (Glu342-Lys290; Glu263-Lys387); a mutation in the A1AT gene causing disruption of either salt bridge causes distinct molecular pathology resulting in reduced serum A1AT levels. Clinically relevant variants can be distinguished by a combination of isoelectric focusing of serum, restriction fragment length analysis of genomic DNA, oligonucleotide probes, and direct sequencing of the variant A1AT genes.

publication date

  • June 24, 1988

has subject area

  • Alleles
  • Gene Expression Regulation
  • Humans
  • Liver Diseases
  • Pulmonary Emphysema
  • alpha 1-Antitrypsin
  • alpha 1-Antitrypsin Deficiency

Research

keywords

  • Journal Article
  • Review

Identity

Language

  • eng

PubMed ID

  • 3289385

Additional Document Info

start page

  • 13

end page

  • 31

volume

  • 84

number

  • 6A