Introduction
Calbindin 1 (CALB1), a calcium-binding protein belonging to the troponin C superfamily, plays a crucial role in calcium regulation. This includes calcium transport, uptake, bone and teeth calcification, and calcium-dependent signaling in neurons, as well as transient roles during embryonic development. CALB1 also exhibits neuroprotective properties against apoptotic cell death. It functions by buffering cytosolic calcium and potentially activating a membrane Ca2+-ATPase and a 3',5'-cyclic nucleotide phosphodiesterase. Interestingly, the biological activity of CALB1 appears to be linked to the redox state of its five cysteine residues.
CALB1 possesses four active calcium-binding domains and two modified domains that seem to have lost their calcium-binding capacity. Its expression is primarily observed in neural tissues, with brain synthesis being independent of vitamin-D-derived hormones.
Dysregulation of CALB1 has been implicated in neurological disorders such as epilepsy, amyotrophic lateral sclerosis, and Huntington's disease. Notably, neurons in the brains of Huntington's disease patients exhibit CALB1 depletion.
Description
Recombinant human CALB1, produced in E. coli, is a non-glycosylated polypeptide chain consisting of 261 amino acids (1-261 a.a.). With a molecular weight of 30kDa, it is purified using proprietary chromatographic techniques.
Physical Appearance
A clear, colorless solution that has been sterilized by filtration.
Formulation
The CALB1 protein solution is supplied in a buffer containing 20mM Tris-HCl (pH 8.0), 1mM DTT, 10% glycerol, and 2mM EDTA.
Stability
For short-term storage (up to 2-4 weeks), the product can be stored at 4°C. For extended storage, freezing at -20°C is recommended.
To ensure long-term stability, adding a carrier protein such as HSA or BSA (0.1%) is advised.
Repeated freezing and thawing should be avoided.
Purity
The purity of the CALB1 protein is greater than 95.0% as determined by SDS-PAGE analysis.
Synonyms
Calbindin, Vitamin D-dependent calcium-binding protein, avian-type, Calbindin D28, D-28K, CALB1, CAB27, CALB, calbindin 1 28kDa.
Amino Acid Sequence
MAESHLQSSL ITASQFFEIW LHFDADGSGY LEGKELQNLI QELQQARKKA GLELSPEMKT FVDQYGQRDD GKIGIVELAH VLPTEENFLL LFRCQQLKSC EEFMKTWRKY DTDHSGFIET EELKNFLKDL LEKANKTVDD TKLAEYTDLM LKLFDSNNDG KLELTEMARL LPVQENFLLK FQGIKMCGKE FNKAFELYDQ DGNGYIDENE LDALLKDLCE KNKQDLDINN ITTYKKNIMA LSDGGKLYRT DLALILCAGD N.