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The nutritional significance of naturally occurring toxins in plant foodstuffs
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8th World Consre~ on Animal, Plant and Microbial Toxlnm
THE I~ITRITIENAL SIGNIFICANCE 0P N A I I ~ Y OC~ING TOXINS IN PLANT H E D S r U ~ S By Irvin R. L I ] ~ . Dept. Biochemistry, College of Biological Sciences, University o f Minnesota, St. P a u l , Minnesota 55108, USA A wide v a r i e t y o f ccmponnds which are known t o produce a d v e r s e p h y s i o l o g i c a l e f f e c t s i n e x p e r i m e n t a l animals occur n a t u r a l l y i n many p l a n t foods commonly consumed by man. The l e g t ~ e s have r e c e i v e d t h e most a t t e m t i a n i n t h i s r e g a r d . Legumes c o n t a i n i n h i b i t o r s of ~ l i a n d i g e s t i v e enzymes which a r e r e s p o n s i b l e f o r growth i n h i b i t i o n and h y p e r t r o p h y and h y p e r p l a s i a o f t h e p a n c r e a s when a n i ~ l s a r e f e d legumes which have n o t r e c e i v e d p r o p e r h e a t t r e a t m e n t . The c h r o n i c i n g e s t i o n of raw soy f l o u r eve~,.lly r e s u l t s i n n e o p l a s t i c changes i n t h e p a n c r e a s . P a r a l l e l i n g t h e d i s t r i b u t i o n o f t r y p s i n i n h i b i t o r s i n legumes a r e l e c t i n s which, by c a u s i n g damage t o t h e m i c r o v i l l i o f t h e i n t e s t i n a l border, can a l s o l e a d t o growth r e t a r d a t i o n and t h e e v e n t u a l d e a t h o f t h e animal. Brief mention will also be made of other toxicants in legumes i n c l u d i n g goitrogeas, cyanogens, and the probable causative factors of lathyrism and favism in ~a~ns. Fortunately, by suitable processing techniques and by plant breeding, many of these natural toxicants can be destroyed or eliminated so they no longer pose a serious threat to ~,....~ health.
KEY ~RDS Naturally occurring toxins]plant foodstuffs
REC~qT PROGRESS ON THE STI~CTJRE AND FUNCTION OF THE ACETYLCHOLINE RECEPTOR JEAN-PIERRE CHANGEDX, UNIT~ DE NEUROBIOLOGIE MOL~.CULAIRE, INSTITIT PASTEUR, 75724 PARIS CEDEX 15 The acetylcholine receptor protein from Torpedo is a well-identified heterologous pentameter (a2 8y6) made up from four distinct subunits.
The amino-acid sequences of
the four subunits is known b y inference from the nucleotide sequence of cE~A clones. The tran~m~-~rane folding of the subunits is discussed in terms of primary structure data on the basis of peptide mapping after selective labelling of the acetylcholine binding site, of a high affinity site for non-competitive blockers and of the peptide segments which contact the lipid bilayer.
Hypotheses concerning the organization of
the ion channel and its regulation by allosteric transitions are discussed.
Data about a contribution of the peripheral protein of 43,000 dalton v I on the agregatio~ and stabilisatio~ of the acetylchollne receptor protein in the subsynaptic membrane are presented.
An eventual role of the u I protein as an intermediate piece
between the postsynaptio membrane and the cytoskeletc~ is discussed.
Finally, data
about the regulatiQn of acetylcholine receptor biosynthesis by the state of activity of in vitro developing chick myotubes are shown.
8th World Consre~ on Animal, Plant and Microbial Toxlnm
THE I~ITRITIENAL SIGNIFICANCE 0P N A I I ~ Y OC~ING TOXINS IN PLANT H E D S r U ~ S By Irvin R. L I ] ~ . Dept. Biochemistry, College of Biological Sciences, University o f Minnesota, St. P a u l , Minnesota 55108, USA A wide v a r i e t y o f ccmponnds which are known t o produce a d v e r s e p h y s i o l o g i c a l e f f e c t s i n e x p e r i m e n t a l animals occur n a t u r a l l y i n many p l a n t foods commonly consumed by man. The l e g t ~ e s have r e c e i v e d t h e most a t t e m t i a n i n t h i s r e g a r d . Legumes c o n t a i n i n h i b i t o r s of ~ l i a n d i g e s t i v e enzymes which a r e r e s p o n s i b l e f o r growth i n h i b i t i o n and h y p e r t r o p h y and h y p e r p l a s i a o f t h e p a n c r e a s when a n i ~ l s a r e f e d legumes which have n o t r e c e i v e d p r o p e r h e a t t r e a t m e n t . The c h r o n i c i n g e s t i o n of raw soy f l o u r eve~,.lly r e s u l t s i n n e o p l a s t i c changes i n t h e p a n c r e a s . P a r a l l e l i n g t h e d i s t r i b u t i o n o f t r y p s i n i n h i b i t o r s i n legumes a r e l e c t i n s which, by c a u s i n g damage t o t h e m i c r o v i l l i o f t h e i n t e s t i n a l border, can a l s o l e a d t o growth r e t a r d a t i o n and t h e e v e n t u a l d e a t h o f t h e animal. Brief mention will also be made of other toxicants in legumes i n c l u d i n g goitrogeas, cyanogens, and the probable causative factors of lathyrism and favism in ~a~ns. Fortunately, by suitable processing techniques and by plant breeding, many of these natural toxicants can be destroyed or eliminated so they no longer pose a serious threat to ~,....~ health.
KEY ~RDS Naturally occurring toxins]plant foodstuffs
REC~qT PROGRESS ON THE STI~CTJRE AND FUNCTION OF THE ACETYLCHOLINE RECEPTOR JEAN-PIERRE CHANGEDX, UNIT~ DE NEUROBIOLOGIE MOL~.CULAIRE, INSTITIT PASTEUR, 75724 PARIS CEDEX 15 The acetylcholine receptor protein from Torpedo is a well-identified heterologous pentameter (a2 8y6) made up from four distinct subunits.
The amino-acid sequences of
the four subunits is known b y inference from the nucleotide sequence of cE~A clones. The tran~m~-~rane folding of the subunits is discussed in terms of primary structure data on the basis of peptide mapping after selective labelling of the acetylcholine binding site, of a high affinity site for non-competitive blockers and of the peptide segments which contact the lipid bilayer.
Hypotheses concerning the organization of
the ion channel and its regulation by allosteric transitions are discussed.
Data about a contribution of the peripheral protein of 43,000 dalton v I on the agregatio~ and stabilisatio~ of the acetylchollne receptor protein in the subsynaptic membrane are presented.
An eventual role of the u I protein as an intermediate piece
between the postsynaptio membrane and the cytoskeletc~ is discussed.
Finally, data
about the regulatiQn of acetylcholine receptor biosynthesis by the state of activity of in vitro developing chick myotubes are shown.