is mucin present in saliva
Although some mucins are membrane-bound due to the presence of a hydrophobic membrane-spanning domain that favors retention in the plasma membrane, most mucins are secreted onto mucosal surfaces or secreted to become a component of saliva.ature mucins are composed of two distinct regions: 1  The amino-and carboxy-terminal regions are very lightly glycosylated, but rich in cysteines. 2  A large central region formed of multiple tandem repeats of 10 to 80 residue sequences in which up to half of the amino acids are serine or threonine.