ABSTRACT
A v a rie ty of in d irec t approaches have been used in o rd e r to in v es tig a te th e functions o f enzym es in v ivo , most of which have been
employed in te s ts w ith one o r an o th e r p lan t 1 ,4 -$ -g lucanase . M eth ods include m easurem ents of enzyme k in e tic s and s u b s tra te spec ifi c ities in v itro in o rd e r to define p robab le lim its to reaction ra te s and d irec tions and to th e ran g e of p o ten tia l s u b s tra te s in v ivo. L ikew ise, histochem ical s tu d ie s of $ -g lucanase d is tr ib u tio n , p a r t ic u la rly those u s in g immunochemical m ethods, can specify p rec ise ly w here in th e cell th is p a r tic u la r enzyme accum ulates and th e re b y focus a tten tio n on p o ten tia l su b s tra te s a t th a t s i te . Such in d irec t o b se rv a tio n s a re u se fu l for defin ing how l,4 -$ -g lu c a n a se could o r might function in v ivo , b u t th e y u sua lly lack th e cau se -an d -e ffec t elem ent needed fo r r ig o ro u s dem onstration of function in th e liv ing cell.
