Somatomedin B
Encyclopedia
Somatomedin B is a serum
factor of unknown function, is a small cysteine-rich peptide, derived proteolytically from the N-terminus of the cell-substrate adhesion
protein vitronectin
. Cys-rich somatomedin B-like domains are found in a number of proteins, including plasma-cell membrane glycoprotein (which has nucleotide pyrophosphate and alkaline phosphodiesterase I activities) and placental protein 11 (which appears to possess amidolytic activity).
The SMB domain of vitronectin has been demonstrated to interact with both the urokinase receptor and the plasminogen activator inhibitor-1 (PAI-1) and the conserved cysteines of the NPP1 somatomedin B-like domain have been shown to mediate homodimerization. As shown in the following schematic representation below the SMB domain contains eight Cys residues, arranged into four disulfide bond
s. It has been suggested that the active SMB domain may be permitted considerable disulfide bond heterogeneity or variability, provided that the Cys25-Cys31 disulfide bond is preserved. The three dimensional structure of the SMB domain is extremely compact and the disulfide bonds are packed in the centre of the domain forming a covalently bonded core. The structure of the SMB domain presents a new protein fold, with the only ordered secondary structure being a single-turn alpha-helix and a single-turn 3(10)-helix.
xxCxxxxxxCxxxxxxxxxCxCxxxCxxxxxCCxxxxxCxxxxx
********************
'C': conserved cysteine probably involved in a disulfide bond.
'*': position of the pattern.
; PRG4
; SUSD2; VTN;
Serum
Serum may refer to:*Blood serum, a component of blood which is collected after coagulation.**Antiserum, blood serum with specific antibodies for passive immunity*Serous fluid, any clear bodily fluid*any drug derived from an animal's blood or serous fluid...
factor of unknown function, is a small cysteine-rich peptide, derived proteolytically from the N-terminus of the cell-substrate adhesion
Cell adhesion
Cellular adhesion is the binding of a cell to a surface, extracellular matrix or another cell using cell adhesion molecules such as selectins, integrins, and cadherins. Correct cellular adhesion is essential in maintaining multicellular structure...
protein vitronectin
Vitronectin
Vitronectin also known as VTN is a protein that in humans is encoded by the VTN gene.The protein encoded by this gene is a member of the pexin family...
. Cys-rich somatomedin B-like domains are found in a number of proteins, including plasma-cell membrane glycoprotein (which has nucleotide pyrophosphate and alkaline phosphodiesterase I activities) and placental protein 11 (which appears to possess amidolytic activity).
The SMB domain of vitronectin has been demonstrated to interact with both the urokinase receptor and the plasminogen activator inhibitor-1 (PAI-1) and the conserved cysteines of the NPP1 somatomedin B-like domain have been shown to mediate homodimerization. As shown in the following schematic representation below the SMB domain contains eight Cys residues, arranged into four disulfide bond
Disulfide bond
In chemistry, a disulfide bond is a covalent bond, usually derived by the coupling of two thiol groups. The linkage is also called an SS-bond or disulfide bridge. The overall connectivity is therefore R-S-S-R. The terminology is widely used in biochemistry...
s. It has been suggested that the active SMB domain may be permitted considerable disulfide bond heterogeneity or variability, provided that the Cys25-Cys31 disulfide bond is preserved. The three dimensional structure of the SMB domain is extremely compact and the disulfide bonds are packed in the centre of the domain forming a covalently bonded core. The structure of the SMB domain presents a new protein fold, with the only ordered secondary structure being a single-turn alpha-helix and a single-turn 3(10)-helix.
xxCxxxxxxCxxxxxxxxxCxCxxxCxxxxxCCxxxxxCxxxxx
********************
'C': conserved cysteine probably involved in a disulfide bond.
'*': position of the pattern.
Human proteins containing this domain
ENPP1; ENPP2; ENPP3ENPP3
Ectonucleotide pyrophosphatase/phosphodiesterase family member 3 is an enzyme that in humans is encoded by the ENPP3 gene.-Further reading:...
; PRG4
PRG4
Proteoglycan 4 or lubricin is a protein that in humans is encoded by the PRG4 gene. This protein acts as a joint/intimal cell lubricant.- Function :...
; SUSD2; VTN;