Ronnie is, as always in matters histochemical, absolutely correct.  In
muscle an increase in acid phospatase activity suggests a decrease in acid
maltase activity.  So demonstrating acid phos may be worthwhile.

Andy Shand


ref. Muscle biopsy: A laboratory investigation by Mike Loughlin

-----Original Message-----
From: Ronnie_Houston@bshsi.com [mailto:Ronnie_Houston@bshsi.com]
Sent: 02 July 2002 17:52
To: Anacko, Nancy L.; histonet@pathology.swmed.edu
Subject: Re[2]: acid maltase





     I'm sorry Nancy,

     but they are two completely different enzymes, that catalyze two
totally
     different reactions. The only similarities are that they are both acid
     hydrolases, and are present in lysosomes, but that's like saying a Kia
and
     a Lexus are both cars.

     Acid phosphatase (EC 3.1.3.2) catalyzes the hydrolysis of esters of
     orthophosphoric acid. It also nydrolyses pyrophosphate compounds and
acts
     as a transphosphorylase. It has an optimum pH of between 4 and 5. Acid
     phosphatase is mainly found in lysosomes. However there are also
     extralysosomal acid phosphatases found in endoplasmic reticulum. It is
     possible to differentiate the acid phosphatases by their sensitivity to
     various inhibitors. Acid phosphatase activity is high in spleen,
kidney,
     liver, intestine, and adrenals.

     Acid maltase (EC 3.1.3.20), also know as acid alpha-d-glucosidase, in
     simple terms breaks down maltose to glucose. It has a optimal pH of 5.
Acid
     maltase is present in liver kidney and brain. A deficiency of acid
maltase
     leads to Pompe's disease (type II glycogenosis). There is no enzyme
     histochemical method for the intracellular localization of acid
maltase;
     only the total activity of acid maltase can be demonstrated in unfixed
     cryostat sections using a semi-permeable membrane technique.
(Incidently,
     in case you are interested, I checked my notes and the most suitable
     substrate for alpha-d-glucosidase is
     5-Br-4-Cl-3-indoxyl-alpha-glucoside)

     Good luck

     Ronnie Houston
     Regional Histology Operations Manager
     Bon Secours Health Partners Laboratories
     5801 Bremo Road
     Richmond, VA 23226



______________________________ Reply Separator
_________________________________
Subject: RE: acid maltase
Author:  "Anacko, Nancy L."  at BSHSIBTW
Date:    7/1/02 3:07 PM




       hi ronnie,
       thanks for answering my questions. the doc here insists that
       one (either
       acid maltase or acid phosphatase)is a by-product of the other ? let
me
       know.
       thanks nancy

       -----Original Message-----
       From: Ronnie_Houston@bshsi.com
       [mailto:Ronnie_Houston@bshsi.com]
       Sent: Monday, July 01, 2002 1:38 PM
       To: Server, Histonet; Anacko, Nancy L.
       Subject: Re: acid maltase





            Nancy

            Unless you are intending on using a semi-permeable
       membrane technique
       for
            the enzyme histochemical reaction, forget it. The enzyme
       is extremely
            soluble, and you will lose it all in your incubation
       media. I believe
       there
            are commercial suppliers of an antibody to acid maltase,
       why not try
            immunocytochemistry?

            Acid maltase bears no similarity to acid phosphatase, and
       the salt you
       have
            mentioning is not a specific substrate for acid maltase,
       but for acid
            phosphatase. There are a couple,of hard-to-find substrates
       that are
            specific for acid maltase, one of which is
       2-napthol-alpha-glucoside
       (can't
            remember the others offhand)

            Suggest you read "Histochemistry" Vol 3, edited by Peter
       Stoward, or
            "Enzyme Histochemistry: A Laboratory Manual" by Lojda et
       al (this is
            out-of-print - but you may be able to borrow it through a
       library)
       before
            embarking on this.


            Ronnie Houston
            Regional Histology Operations Manager
            Bon Secours Health Partners Laboratories
            5801 Bremo Road
            Richmond, VA 23226


       ______________________________ Reply Separator
       _________________________________
       Subject: acid maltase
       Author:  "Anacko, Nancy L."  at BSHSIBTW
       Date:    7/1/02 12:08 PM




              can anyone help me with this "acid maltase" stain ??? i
       need an
              0.2m acetate
              buffer....can i get this pre-made ? if so where ?
              if i can't what type of sodium acetate do i
       use...trihydrate or
              anhydrous
              ??? also where can i order the sodium alpha naphthyl
       phosphate
              from and does
              it go by adifferent name ?? also is acid phosphatase
              azo-coupling technique
              the same as an acid maltase stain ?? HELP :-/> thanks
       nancy