CRISP-4, Recombinant, Mouse, 6-His-Tag (Cysteine-rich Secretory Protein 4, Crisp4)

CRISP-4 is one of several CRISPs (cysteine-rich secretory proteins) that contain 16 invariant cysteine residues and show structural homolgy to snake, insect, and lizard venom proteins. These proteins consist of an N-terminal SCP/CAP domain, a hinge region, and a cysteine-rich CRISP domain. CRISPs are expressed in discrete but overlapping regions of the male reproductive tract and play a role in spermatozoa adhesion with Sertoli cells and oocytes, decapacitation, and the acrosomal reaction. CRISP-4 facilitates the progesterone-induced acrosomal reaction by inhibiting calcium conductance through the TRPM8 channel on sperm. Mouse CRISP-4 is secreted as a 32kD protein in the epididymis (primarily the caput region), vas deferens, and seminal vesicle. It is also associated with spermatozoa from the testis and caudal epididymis as a 26-28kD molecule. Its expression is induced at the onset of puberty in an androgen-dependent fashion. Mouse and rat CRISP-1 are additionally expressed in salivary glands, while CRISP-4 is not. Expression patterns, genomic structure, and sequence conservation indicate that CRISP-4 in mouse and rat are the likely orthologs of human CRISP-1. Mature mouse CRISP-4 shares 90% and 64% aa sequence identity with rat CRISP-4 and human CRISP-1, respectively. Mature mouse CRISP-4 shares 38%-43% aa sequence identity with mouse CRISP-1, -2, and -3. Source: Recombinant corresponding to aa22-250 from mouse CRISP-4, fused to 6-His-tag at C-terminal expressed in Chinese Hamster Ovary cell line, CHO. Molecular Weight: ~27.2kD Biological Activity: Measured by the ability of the immobilized protein to support the adhesion of NTera-2 human testicular embryonic carcinoma cells (ATCC: CRL-1973). The ED50 for this effect is typically 0.3-1.5ug/ml after a 1h incubation at 37 degrees C. Endotoxin: ~1EU/1ug (LAL) Storage and Stability: Lyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile buffer. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Reconstituted product is stable for 3 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.