In vitro integration of the polytopic, transmembrane lactose permease into membrane vesicles from Escherichia coli is demonstrated. To this end the enzyme was synthesized in a homologous, cell-free transcription-translation system. In this system, synthesis occurred in an essentially membrane-free environment leading to the formation of lactose permease aggregates, which were resistant to prote...

The disaccharide lactose is one of the main components of milk. During the digestion, it is hydrolysed by the enzyme ß-galactosidase into glucose and galactose. With the exception of the Caucasian populations the lactase activity decreases in most people in the age of weaning. After the ingestion of large amounts of lactose, symptoms as bloating, flatulence, abdominal pain and diarrhea can occu...

The aim of this study was to establish a retrospective evaluation and comparison of the hydrogen/methane (H2/CH4) breath test and genetic test (C/T-13910 polymorphism) results in lactose malabsorption testing. In total 263 consecutive patients with suspected lactose malabsorption were included in this study. They underwent the H2/CH4 breath test following the ingestion of 50 g lactose and were ...

Fractionation of rat mammary gland extracts by ion eschange chromatography has led to the isolation of a new low molecular weight derivative of neuraminic acid. This compound appears to be a sulfuric ester of neuramin-lactose (1) and, therefore, the name neuramin-lactose sulfate is here proposed for it. Glands obtained from the first to the sixth da.y after delivery contained an average of 3.4 ...

β-galactosidase simply known as lactase is a significant enzyme in food industry mainly used to hydrolyse lactose in milk. In addition to provide lactose free milk for lactose intolerant people, hydrolysis of lactose avoids textural problems in frozen milk products. β-galactaosidase from different sources has been immobilized on many various type of matrixes including chitosan, alginate, sepabe...

A lactose-bearing norbornene imide template was polymerized using (Cy3P)2Cl2Ru=CHPh to produce a lactose-substituted neoglycopolymer. The resulting polymer showed a 100-fold overall increase in inhibitory potency (5-fold increase on a per saccharide residue basis) compared to monomeric lactose in both a galectin-binding assay and an Erythrina corallodendrum hemagglutination assay.

1. The effects of hypophysectomy and replacement therapy with sheep prolactin and bovine growth hormone on the lactose synthetase activity of the mammary glands of lactating rabbits were studied. 2. There was an approximately fourfold decline in the lactose synthetase activity of homogenates calculated on a DNA basis within 6-7 days of hypophysectomy. Prolactin reversed this decline but growth ...

-Galactosidase is widely used in food industry to improve sweetness, solubility, flavor and digestibility of dairy products (Richmond, Gray, and Stine, 1981; Grosova et al. 2008a) . Enzymatic hydrolysis of lactose by galactosidase is one of the most popular technologies to produce lactose reduced milk and related dairy products for consumption by lactose intolerant people (Ladero, Santos, and G...

Extracts and tissue culture supernatants of axenic forms of T. rangeli were assayed for the presence of sialidase and trans-sialidase activities. Using sialyl(alpha 2-3)lactose, sialyl(alpha 2-6)lactose, poly(alpha 2-8)N-acetylneuraminic acid, fetuin and 4-methylumbelliferyl-N-acetylneuraminic acid as sialic acid donors, and lactose as a sialic acid acceptor, no trans-sialidase activity was det...

The Gram-negative bacterium E. coli is the host of choice for a multitude of used recombinant proteins. Generally, cultivation is easy, media are cheap, and a high product titer can be obtained. However, harsh induction procedures using isopropyl β-d-1 thiogalactopyranoside as inducer are often referred to cause stress reactions, leading to a phenomenon known as "metabolic" or "product burden"....