Venezia by PVII

Tom BaranowskiBuford L. Nichols, Jr., MD

Professor of Pediatrics
Baylor College of Medicine
Director Emeritus, CNRC
bnichols@bcm.tmc.edu

Attending Physician
Section of GI and Nutrition
Texas Children's Hospital

Maltase-Glucoamylase: Regulator of Starch Digestion

My research focuses on regulation of the brush border enzyme, maltase-glucoamylase, which is required for final conversion of the products of starch digestion produced by salivary and pancreatic amylase into glucose for absorption.  Having cloned and sequenced the cDNA for maltase-glucoamylase and shown that the loss of maltase-glucoamylase activity in malnourished infants is due to mucosal atrophy and not to reduced translation, the regulation of maltase-glucoamylase in children with both normal and abnormal mucosal histology is now being investigated.  Of particular interest is whether activity is modulated at the transcriptional level. 

To date, one infant with a mutation in the coding region of maltse-glucoamylase and reduced efficiency of small intestinal starch digestion has been found and efforts are underway to locate others.  Planned studies in these children with maltse-glucoamylase mutations will examine the metabolic consequences of reduced small intestinal and increased colonic starch digestion.  The prevalence of human maltse-glucoamylase deficiency also is under active investigation as part of the search for children with mutations in the maltse-glucoamylase gene.

Representative publications:

Nichols BL. Icie Macy and Elsie Widdowson: pioneers of child nutrition and growth. J Nutr. 133(11):3690-3692, 2003.

Nichols, BL, Avery, SE, Sen, P,  Swallow, DM, Hahn, D, Sterchi, EE The Maltase-Glucoamylase Gene:  Common Ancestry to Sucrase-Isomaltase With Complementary Starch Digestion Activities.  Proc. Natl. Acad. Sci.  100: 1432-1437 2003

Nichols, BL. Dietary management of the malnourished child with chronic diarrhea: both  nurture and nature. J. Pediat Gastroenter Nutr  2003; 36: 168-169.

Karnsakul,W, Luginbuehl,U, Hahn, D, Sterchi, E, Avery, S, Sen, P, Swallow, D, Nichols, B. Disaccharidase activities in dyspeptic children: Biochemical and molecular investigations of maltase-glucoamylase. J. Pediat Gastroenter Nutr 2002; 551-556

Nichols, BL, Avery, SE, Karnsakul, W, Jahoor, F,  S, Sen, Sterchi, EE. Congenital   Maltase-glucoamylase Deficiency Associated with Lactase and Sucrase Deficiencies:  Pleiotropic gene regulation? J. Pediat Gastroenter Nutr  2002; 35: 573-579.

Karnsakul, W, Luginbuehl, U,  Hahn, D, Sterchi, E,  Avery, S,  Sen, P,  Swallow, D,  Nichols, B.  Disaccharidase Activities in Dyspeptic Children: Biochemical and Molecular Investigations of Maltase-Glucoamylase Activity.  J. Pediat Gastroenter Nutr  2002; 35:; 551-556.

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