Cytidine is a nucleoside formed by a cytosine attached to a ribose ring via a beta-N1-glycosidic bond. DNA is methylated on cytidines by DNA methylases (DNMTs)to generate 5-methylcytidine (5-mC), a potent epigenetics marker and regulator of gene expression. The reverse reaction (cytidine demethylation) starts with its oxidation to hydroxymethyl- (5-hmC), formyl- (5-fC), and carboxy- (5-caC) cytidine. Several enzymes, including the Tet family of proteins have been implicated in cytidine demeth

Acrosin is the major proteinase present in the acrosome of mature spermatozoa. It is a typical serine proteinase with trypsin-like specificity. It is stored in the acrosome in its precursor form, proacrosin. The active enzyme functions in the lysis of the zona pellucida, thus facilitating penetration of the sperm through the innermost glycoprotein layers of the ovum. The mRNA for proacrosin is synthesized only in the postmeiotic stages of spermatogenesis. In humans proacrosin first appears in t

Acrosin is the major proteinase present in the acrosome of mature spermatozoa. It is a typical serine proteinase with trypsin-like specificity. It is stored in the acrosome in its precursor form, proacrosin. The active enzyme functions in the lysis of the zona pellucida, thus facilitating penetration of the sperm through the innermost glycoprotein layers of the ovum. The mRNA for proacrosin is synthesized only in the postmeiotic stages of spermatogenesis. In humans proacrosin first appears in t

Epitope tagging is a recombinant DNA method by which a protein encoded by a cloned gene is made immunoreactive to a known antibody. Major areas ofapplication include monitoring protein expression, localizing proteins at thecellular and subcellular levels, and protein purification, as well as the analysis of protein topology, dynamics and interactions. Due to their small size, theyare unlikely to affect the tagged protein's biochemical properties.S1 tag is an epitope tag composed of a nine-r

CBP tag is a calmodulin-binding peptide, KRRWKKNFIAVSAANRFKKISSSGAL, derived from skeletal/cardiac muscle myosin light chain kinase 2.

Yellow fluorescent protein (YFP) is a genetic mutant of green fluorescent protein (GFP) originally derived from the jellyfish Aequorea victoria. Its excitation peak is 514 nm and its emission peak is 527 nm. Like the parent GFP, YFP is a useful tool in cell and molecular biology thanks to its properties useful for fluorescence microscopy.