General Properties of Saliva Proteins 173 



are quite readily hydrolysed under the acid conditions commonly 

 used for isolation of mucins. 



On the basis of chemical studies, mucoproteins from various 

 sources have been divided up into three broad classes. 



(«) 



Albumin 



P 



Point of 

 application 



(b) 



Fig. 9.2. Densitometry of paper electrophoretograms of (a) human parotid 

 saliva: the peak marked A contains the amylase activity, (b) human submaxillary 

 saliva. 



The arrow marks point of application, note that some fractions move towards the cathode. 

 The notations Alb, a,, a,, ft indicate the portions of these fractions in plasma (Kosthn and Rauch, 

 1957). 



i. Fucomucins — composed of about equal amounts of fucose 

 (6-deoxygalactose), glucosamine, galactosamine and galactose. 



2. Sialomucins — probably composed exclusively of sialic acid 

 and N-acetylgalactosamine. 



3. Mucoitin sulphuric acid— composed of equal amounts of N- 

 acetyl-glucosamine, glucuronic acid, and sulphuric acid. 



