Clusterin Human, His

Clusterin, also known as Apolipoprotein J (APO-J), is a protein with a molecular weight of 75-80 kDa. It exists as a disulfide-linked heterodimer and is heavily glycosylated, containing approximately 30% N-linked carbohydrates rich in sialic acid. However, truncated forms of Clusterin have also been found that target the nucleus. The precursor polypeptide chain undergoes proteolytic cleavage, removing a 22-amino acid secretory signal peptide and subsequently dividing the protein between residues 227 and 228. This process generates the a and b chains, which assemble in an anti-parallel fashion to form the heterodimeric molecule. Five disulfide bridges link the cysteine-rich centers of these chains. Two predicted coiled-coil alpha-helices and three predicted amphipathic alpha-helices flank these centers. Clusterin exhibits a high degree of sequence homology across various species, ranging from 70% to 80%. Its expression is nearly ubiquitous in most mammalian tissues, and it can be found in various bodily fluids, including plasma, milk, urine, cerebrospinal fluid, and semen. Clusterin possesses the ability to bind to and form complexes with a wide range of molecules, including immunoglobulins, lipids, heparin, bacteria, complement components, paraoxonase, beta-amyloid, leptin, and others. As a result of its interactions, Clusterin has been implicated in numerous biological processes. These include phagocyte recruitment, aggregation induction, prevention of complement attack, inhibition of apoptosis, membrane remodeling, lipid transport, hormone transport, and scavenging. Despite extensive research, the exact function of Clusterin remains unclear. One prominent hypothesis suggests that it acts as an extracellular chaperone, protecting cells from stress-induced damage caused by the accumulation of degraded and misfolded protein precipitates. Clusterin expression levels are often altered in various pathological and clinically relevant conditions. These include cancer, organ regeneration, infection, Alzheimer's disease, retinitis pigmentosa, myocardial infarction, renal tubular damage, autoimmunity, and others. Depending on the specific condition, Clusterin can be upregulated or downregulated at both the mRNA and protein levels.

Recombinant Human Clusterin, expressed in E. coli, is a single, non-glycosylated polypeptide chain comprising 463 amino acids (specifically, amino acids 23-449). It has a molecular weight of 54.1 kDa. The Clusterin protein is fused to a 36 amino acid His-tag at its N-terminus and is purified using proprietary chromatographic techniques.

A clear, colorless solution that has been sterilized by filtration.

The Clusterin protein solution has a concentration of 0.5 mg/ml and is supplied in a buffer containing 20 mM Tris-HCl (pH 8.0), 0.15 M NaCl, 10% glycerol, and 1 mM DTT.

For short-term storage (up to 2-4 weeks), the product can be stored at 4°C. For extended storage, it is recommended to freeze the product at -20°C. The addition of a carrier protein (0.1% HSA or BSA) is advisable for long-term storage. Repeated freezing and thawing of the product should be avoided.

The purity of the Clusterin protein is determined by SDS-PAGE to be greater than 85%.

CLI, AAG4, APOJ, KUB1, SGP2, SGP-2, SP-40, TRPM2, TRPM-2, MGC24903, Clusterin, ging-associated gene 4 protein, Apolipoprotein J,Complement cytolysis inhibitor, Complement-associated protein SP-40,40, Ku70-binding protein 1, NA1/NA2, Testosterone-repressed prostate message 2, CLU.

Escherichia Coli.

MRGSHHHHHH GMASMTGGQQ MGRDLYDDDD KDRWGSDQTV SDNELQEMSN QGSKYVNKEI QNAVNGVKQI KTLIEKTNEE RKTLLSNLEE AKKKKEDALN ETRESETKLK ELPGVCNETM MALWEECKPC LKQTCMKFYA RVCRSGSGLV GRQLEEFLNQ SSPFYFWMNG DRIDSLLEND RQQTHMLDVM QDHFSRASSI IDELFQDRFF TREPQDTYHY LPFSLPHRRP HFFFPKSRIV RSLMPFSPYE PLNFHAMFQP FLEMIHEAQQ AMDIHFHSPA FQHPPTEFIR EGDDDRTVCR EIRHNSTGCL RMKDQCDKCR EILSVDCSTN NPSQAKLRRE LDESLQVAER LTRKYNELLK SYQWKMLNTS SLLEQLNEQF NWVSRLANLT QGEDQYYLRV TTVASHTSDS DVPSGVTEVV VKLFDSDPIT VTVPVEVSRK NPKFMETVAE KALQEYRKKH REE.