Abstract
The cDNA sequence encoding the bovine fetal protein fetuin is reported. The deduced amino acid sequence is identical with that obtained from amino acid sequencing. The protein is a single chain preceded by a signal sequence. The three N-linked glycosylation sites have been determined. The sequence of fetuin shows over 70% similarity to human alpha 2HS glycoprotein. All of the cysteine residues are conserved in both proteins, suggesting that fetuin has the same arrangement of disulfide loops as alpha 2HS glycoprotein and may also be a member of the cystatin family. Southern blot analysis indicates that a single gene codes for fetuin. No evidence for a separate gene for a bovine alpha 2HS glycoprotein was obtained; thus, fetuin in cattle and alpha 2HS glycoprotein in the human are equivalent proteins.
Highlights
All of the cysteine residues are conserved in both proteins, suggesting that fetuin has the same arrangement of disulfide loops as azHS glycoprotein and may be a member of the cystatin family
The aim of the present study was to investigate the structural homology between bovine fetuin and human
A computer-aided search of the Swisspro sequence data base revealed that the only protein homologous to fetuin was the human plasma protein
Summary
All of the cysteine residues are conserved in both proteins, suggesting that fetuin has the same arrangement of disulfide loops as azHS glycoprotein and may be a member of the cystatin family. A2HS glycoprotein is present in human plasma as two polypeptide chains (A and B) held together by a single interchain disulfide bridge [15]. Both chains are encoded by a single mRNA transcript which codes for a connecting sequence partially cleaved before the protein is released into the circulation [16,17]. The aim of the present study was to investigate the structural homology between bovine fetuin and human
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have