Comparative studies of the Spi1 proteins of three equine alpha-1-proteinase inhibitor haplotypes following isolation by affinity chromatography.
1. Antiproteinase deficiency can result in excessive proteinase-induced tissue damage. The major anti-elastase (Spi1) protein of equine alpha 1-proteinase inhibitor (alpha 1-PI) was isolated from the plasma/serum of three common haplotypes (I, L and U). 2. The N-terminal amino acid sequences of the three inhibitors were identical, but were only approx 65-77% homologous with two other published equine Spi1 sequences. 3. All three inhibitors complexed quickly and irreversibly with equine leucocyte proteinase 2A (kass = 2 x 10(7) M-1 sec-1). They were also efficient inhibitors of chymase (rat mast cell proteinase-II; kass = 2 x 10(5) M-1 sec-1; Ki = 2 x 10(-10) M). There was therefore no evidence of deficient inhibition in the Spi1 variants of the I,L and U haplotypes.
Pemberton
A D
AD
Moredun Research Institute, Edinburgh, Midlothian, Scotland, U.K.
Miller
H R
HR
John
H A
HA
Scudamore
C L
CL
D000595:Amino Acid Sequence; D000818:Animals; D002846:Chromatography, Affinity; D006239:Haplotypes; D006736:Horses / Q000097:blood*; D007700:Kinetics; D008407:Mast Cells / Q000201:enzymology; D008969:Molecular Sequence Data; D051381:Rats; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D000515:alpha 1-Antitrypsin / Q000235:genetics*
D015842:Serine Proteinase Inhibitors; D000515:alpha 1-Antitrypsin