INTRODUCTION 313 



The so-called structural polysaccharides should by no means be 

 regarded as metabolically inert material. Already the relatively rapid 

 metabolic turn-over of some of the acid mucopolysaccharides may be 

 taken as evidence of that. It has been suggested that the architecture of the 

 collagen bundles is determined by the type of polysaccharide formed by 

 the cells in various types of connective tissues, and that the polysaccharide 

 in some way or the other influences fibre formation. In embryonic develop- 

 ment and wound healing the fibre formation is preceded by or con- 

 comitant with the formation of mucopolysaccharides. Of these, hyaluronic 

 acid is usually the first produced, followed by sulphated forms. Some kind 

 of template function of the polysaccharides bearing upon secondary or 

 tertiary structure of connective tissue proteins might perhaps be con- 

 ceivable. 



In any event the problems pertaining to formation and metabolic 

 turn-over of the polysaccharides must of course be of great interest in 

 connection with biological structure and function. These problems have 

 been very much to the fore during latter years and Prof. Dorfman and Prof. 

 Hestrin have, as you all know, made outstanding contributions in these 

 fields. We have learned that biosynthesis is not, as was earlier assumed, a 

 simple reversal of the process of hydrolysis. The enzymic polysaccharidic 

 syntheses work with donor substances, a common feature of which is that 

 they consist of a sugar substituted on the anomeric carbon atom. The 

 splitting of the bond between sugar and substituent supplies the energy 

 required for the polymerization. The availability of suitable donors and 

 appropriate enzymes (and perhaps other catalysts) will be the primary 

 factors directing and guiding the formation of the polysaccharides. This 

 field is as fascinating as it is complicated. 



We await with great interest what Prof. Hestrin and Prof. Dorfman 

 have to tell us about their work. 



As with all other sciences progress in the polysaccharide field is very 

 much dependent on the finding of new tools, principles, and methods of 

 investigations. The separation of biological substances in unchanged state 

 from the complex mixture in which they occur in living tissues, is one of 

 the basic methodological problems of biochemistry. Dr. Flodin will give 

 us a report of a new and promising device for the fractionation and 

 separation of biological substances, which seems promising not least for 

 the carbohydrate field, and I should not be surprised if it spread like an 

 epidemic in biochemical laboratories. 



