Inter-alpha-inhibitor in calcium stones.
1. A broad spectrum of proteins has been detected within calcium stones. A newcomer to the field of urolithiasis is the blood protein inter-alpha-inhibitor. Inter-alpha-inhibitor comprises three protein chains linked by chondroitin sulphate: two heavy chains, H1 (65 kDa) and H2 (70 kDa) and a light chain (approx. 30 kDa) most commonly known as bikunin. The physiological function of the two heavy chains is unknown; nor has their presence been reported in urine. However, bikunin has been implicated in various renal diseases, including urolithiasis. 2. This study was undertaken to determine which chains of inter-alpha-inhibitor are actually present in calcium kidney stones. Organic extracts were obtained from 10 calcium stones and analysed by SDS/PAGE and Western blotting. The H1 and H2 chains of inter-alpha-inhibitor were detected in 9 of the 10 stones, but only one stone contained a protein with a molecular mass close to that of bikunin (30-35 kDa). 3. These results demonstrate for the first time that H1 and H2 are present in stones and show that the bikunin chain of inter-alpha-inhibitor may not be the only part of the molecule implicated in stone formation.
Dawson
C J
CJ
Department of Surgery, Flinders Medical Centre, Bedford Park, South Australia 5042, Australia.
Grover
P K
PK
Kanellos
J
J
Pham
H
H
Kupczyk
G
G
Oates
A
A
Ryall
R L
RL
D000328:Adult; D000368:Aged; D000510:Alpha-Globulins / Q000032:analysis* / Q000737:chemistry; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D011487:Protein Conformation; D015842:Serine Proteinase Inhibitors / Q000032:analysis* / Q000737:chemistry; D014361:Trypsin Inhibitors / Q000032:analysis* / Q000737:chemistry
D000510:Alpha-Globulins; D015842:Serine Proteinase Inhibitors; D014361:Trypsin Inhibitors; C011877:inter-alpha-inhibitor