Sperm-associated antigen 11B
experimentalAlso known as: Human epididymis-specific protein 2, Protein EP2, Sperm antigen HE2, SPAG11B, Q08648
Sperm-associated antigen 11B (SPAG11B), also known as human epididymis-specific protein 2 (HE2) or protein EP2, is an antimicrobial peptide predominantly expressed in the male reproductive tract, particularly the epididymis. Its mechanism of action involves direct antimicrobial activity, specifically demonstrated against *Escherichia coli*, likely through membrane disruption or interference with bacterial cell wall integrity, similar to other cationic antimicrobial peptides. This activity suggests a role in host defense within the reproductive system, protecting sperm from microbial pathogens during maturation and storage. Current research on SPAG11B remains at an experimental stage, with only two PubMed-indexed references available. Key findings have focused on its expression profile and antimicrobial properties, but detailed mechanistic studies, in vivo models, and broader pathogen spectrum analyses are lacking. The limited literature underscores the need for further investigation into its structure-function relationships, regulation, and potential interactions with other reproductive tract components. Clinically, SPAG11B may have relevance in male reproductive health, particularly in preventing or treating genitourinary infections that could impair fertility. However, due to the scarcity of data, its therapeutic potential remains speculative. No clinical trials or translational applications have been reported. For research purposes only — not medical advice.
Key data
MRQRLLPSVTSLLLVALLFPGSSQARHVNHSATEALGELRERAPGQGTNGFQLLRHAVKRDLLPPRTPPYQVHISHREARGPSFRICVDFLGPRWARGCSTGNMechanism of action
Has antimicrobial activity against E.coli (By similarity). Plays a role in the defense response in the male reproductive tract, contributing to sperm maturation, storage and protection (By similarity)
Research & studies
Tryptase expression and activity were upregulated in arthritic joints, while Spag11c expression remained unchanged.; Both lentivirus-mediated hSPAG11B/C and APC366 inhibited tryptase-like activity and late-phase edema.; Tryptase inhibition reduced IL-6 and CXCL1/KC production but did not prevent neutrophil infiltration or cartilage/bone damage.; The study suggests tryptase inhibitors may have palliative but not disease-modifying potential in rheumatoid arthritis.
SPAG11B proteins and peptides are amphipathic and highly hydrophilic based on WHAT and GRAVY analyses.; Secondary structure primarily consists of beta-sheet and random coil, with minor alpha-helix content.; Structures are stable, with most amino acids in permissible regions of Ramachandran plots.; Secondary structure remains unchanged at NaCl concentrations up to 300 mM and pH 3, 7, and 10, indicating salt-tolerant antimicrobial activity.
Frequently asked questions
What is Sperm-associated antigen 11B?
Sperm-associated antigen 11B (SPAG11B), also known as human epididymis-specific protein 2 (HE2) or protein EP2, is an antimicrobial peptide predominantly expressed in the male reproductive tract, particularly the epididymis. Its mechanism of action involves direct antimicrobial activity, specifically demonstrated again
How does Sperm-associated antigen 11B work?
Has antimicrobial activity against E.coli (By similarity). Plays a role in the defense response in the male reproductive tract, contributing to sperm maturation, storage and protection (By similarity)
What is the research status of Sperm-associated antigen 11B?
Sperm-associated antigen 11B is currently classified as experimental, with 2 research references on record. This is for research purposes only and is not medical advice.
What is the molecular weight of Sperm-associated antigen 11B?
Sperm-associated antigen 11B has a molecular weight of approximately 11431 g/mol.
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