Lysozyme (SPACA3) Antibody – Rabbit Polyclonal

The protein encoded by this gene is a sperm surface protein that may be involved in adhesion to the egg prior to fertilization. While the encoded protein has significant similarity to lysozyme at the amino acid level, it has no detectable bacteriocidal activity. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2015]

SPACA3: a single-pass type II sperm surface membrane protein that may be involved in sperm-egg plasma membrane adhesion and fusion during fertilization. It could be a potential receptor for the egg oligosaccharide residue N-acetylglucosamine, which is present in the extracellular matrix over the egg plasma membrane. A member of the Cancer-Testis Antigen (CTA) superfamily. CTAs may play roles in embryonal development and tumor transformation or aspects of tumor progression. CTAs were once thought to be silenced in most normal adult tissues, with limited expression in fetal, placental, testis, and ovarian cells. These proteins are now known to be aberrantly expressed in various cancers and many are capable of eliciting humoral and cellular immune responses. Expressed in testis, epididymis and placenta. Although it belongs to the glycosyl hydrolase 22 family, T122 and N139 are present instead of the conserved Glu and Asp which are active site residues. It is therefore expected that this protein lacks hydrolase activity. Two isoforms of the human protein are produced by alternative splicing. Note: This description may include information from RefSeq and UniProtKB

Protein type: Membrane protein, integral; Cancer Testis Antigen (CTA)

Chromosomal Location of Human Ortholog: 17q11.2

Cellular Component: acrosomal membrane; extracellular region; integral to membrane; lysosome; secretory granule

Molecular Function: lysozyme activity; protein binding

Biological Process: cell wall catabolic process; defense response to Gram-positive bacterium; monocyte activation; peptidoglycan catabolic process; positive regulation of macrophage activation; positive regulation of phagocytosis; response to virus; sperm-egg recognition