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Chemical Compound Review

lactose     (2R,3R,4S,5R,6S)-2- (hydroxymethyl)-6-[(2R...

Synonyms: Aletobiose, Galactinum, Lactin, Lactobiose, Osmolactan, ...
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Disease relevance of Lactin

  • The osmotic stress technique was used to measure changes in macromolecular hydration that accompany binding of wild-type Escherichia coli lactose (lac) repressor to its regulatory site (operator O1) in the lac promoter and its transfer from site O1 to nonspecific DNA [1].
  • Clostridium botulinum serotype B toxins 12S and 16S were separated by using a beta-lactose gel column at pH 6.0; toxin 12S passed through the column, whereas toxin 16S bound to the column and eluted with lactose [2].
  • We have used elements of the E. coli lactose (lac) operon to produce a collection of herpes simplex virus types 1 and 2 glycoprotein D (gD-1 and gD-2) antigens [3].
  • Fifty-six percent of Lac+ transconjugants were resistant to the S. cremoris M12R lytic phage [4].
  • The MDS-fed pigs initially grew slower, but had intestinal dimensions similar to those of LAC-fed siblings when normalized to body weight [5].

High impact information on Lactin

  • The developmental accumulation and localization of PP1 and its mRNA paralleled the phloem lactin, further suggesting an interaction between these phloem-specific proteins [6].
  • In the genus Cucurbita, these filaments are composed of two major proteins: PP1, the phloem filament protein, and PP2, the phloem lactin [6].
  • Low expression levels of Gal-1 correlated with a reduction of RPE migration to 14% of control. beta-Lactose inhibited HGF-induced RPE cell migration to 23% of control [7].
  • About half of the apparent increase in the adaptive mutation rate of recD mutant cells is due to a RecA-dependent increase in episomal copy number and to growth of the Lac- cells on the lactose plates [8].
  • The orientation of the reconstituted LacS protein is a critical factor for the activity of the protein as the kinetics of translocation is very different for opposite directions of transport [9].

Chemical compound and disease context of Lactin


Biological context of Lactin

  • Thus, there is no evidence for clustering of Lac genes into an operon-like regulatory unit.--To further characterize the nature of the Lac- phenotype, the basal and inducible level of beta-galactosidase activity were measured [13].
  • The repeats flank markers conferring lactose utilization (Lac+) and ampicillin resistance (ApR); recombination generates Lac-ApS segregants [14].
  • To study the effect of Gal-1 on RPE migration in vitro, Gal-1 expression was silenced by RNA interference. beta-Lactose was used to saturate extracellular galectins [7].
  • Transconjugants were detected by transfer of Lac+ and were found to exhibit Nisr and harbor a 40-megadalton plasmid (pTR1040) [4].
  • The required stereochemistry of the targeted nucleosides was successfully obtained with use of Grubbs cyclization and Trost allylic alkylation from the carbohydrate chiral template "D-lactose" [15].

Anatomical context of Lactin

  • Rosette formation was inhibited in the presence of 20 mM D-lactose as well as after preincubation of erythrocytes with purified lectin [16].
  • Replacement of the RSV-LTR promoter with the heavy metal-inducible mouse metallothionein-1 promoter in the lacR-responsive unit, as well as the generation of a clonal glioma cell line expressing lacR, did not significantly enhance regulation of DTA in the Lac system [11].
  • Total DNA content of intact small intestines were not different among groups; however, cpm [3H]thymidine/mg intestinal DNA of C and M piglets exceeded (P less than .05) that for L piglets [17].
  • Total protein in the intestines and intestinal mucosa of C pigs exceeded (P less than .01) that for L and M pigs [17].
  • Stomach and pancreas weights among all pigs were similar, although C and M pigs exceeded L pigs in stomach (P less than .01) and pancreas (P less than .01) RNA content [17].

Associations of Lactin with other chemical compounds

  • 6. The relaxant effects of WGA were reversed by addition of 20 mM N-acetyl-D-glucosamine (GlcNAc) and N-acetyl-D-galactosamine (Ga1NAc) but not by alpha-mannose, D-(+)-galactose, and beta-lactose, whereas the endothelin-dependent relaxations to LCA and Con A were unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)[18]
  • Piglets received one of three diets at a low energy intake level, which differed in lactose and protein ratio as follows: low lactose/high protein (LL/HP), control (C), or high lactose/low protein (HL/LP) [19].
  • CBP 32 binds specifically to glycoproteins containing asparagine-linked complex oligosaccharides, and can be eluted from a fetuin affinity matrix by beta-lactose [20].
  • (Ca2+ is required for activation of the classical C pathway via C1q and the lactin pathway via mannose binding lectin (MBL), and the surface of apoptotic cells usually activates the alternative C pathway.) In this study we tested which of the pathways participates in XP cell C3 deposition [21].
  • To search for the target and the mechanism of urea action we measured lactose (lac) and tryptophanase (tna) specific mRNA synthesis in vivo and in vitro [22].

Gene context of Lactin

  • Analysis of the structures reveals specific interactions between Lac repressor and DNA that were not found in previously investigated Lac repressor-DNA complexes [23].
  • Low-level expression of lac was detected in Escherichia coli harboring this expression system when RpoSP6 was uninduced, although very low activities of beta-galactosidase (beta-Gal) were observed which were independent of the presence of pFSP6 [24].
  • This defect does not reflect a loss of all lac operon activity galactoside acetyltransferase from the last gene was synthesized even in strain AB301-105 but at a rate several times lower than normal [25].
  • The lactose (lac) operon promoter is positively regulated by the catabolite gene activator-cyclic AMP complex (CAP) that binds to the DNA located 61.5 bp upstream of the transcription start site [26].
  • The highest level of CAP-independent lac expression (13-fold the level of the wild-type lac promoter) correlated with changes in the -40 to -45 sequence and required an intact RNA polymerase alpha subunit for in vitro expression, as expected for an upstream DNA recognition element [26].

Analytical, diagnostic and therapeutic context of Lactin


  1. Role of hydration in the binding of lac repressor to DNA. Fried, M.G., Stickle, D.F., Smirnakis, K.V., Adams, C., MacDonald, D., Lu, P. J. Biol. Chem. (2002) [Pubmed]
  2. Purification of fully activated Clostridium botulinum serotype B toxin for treatment of patients with dystonia. Arimitsu, H., Inoue, K., Sakaguchi, Y., Lee, J., Fujinaga, Y., Watanabe, T., Ohyama, T., Hirst, R., Oguma, K. Infect. Immun. (2003) [Pubmed]
  3. Bacterial synthesis of herpes simplex virus types 1 and 2 glycoprotein D antigens. Watson, R.J., Weis, J.H., Salstrom, J.S., Enquist, L.W. J. Invest. Dermatol. (1984) [Pubmed]
  4. Streptococcus cremoris M12R transconjugants carrying the conjugal plasmid pTR2030 are insensitive to attack by lytic bacteriophages. Steenson, L.R., Klaenhammer, T.R. Appl. Environ. Microbiol. (1985) [Pubmed]
  5. Intestinal amino acid and monosaccharide transport in suckling pigs fed milk replacers with different sources of carbohydrate. Vega, Y.M., Puchal, A.A., Buddington, R.K. J. Nutr. (1992) [Pubmed]
  6. Molecular characterization of a phloem-specific gene encoding the filament protein, phloem protein 1 (PP1), from Cucurbita maxima. Clark, A.M., Jacobsen, K.R., Bostwick, D.E., Dannenhoffer, J.M., Skaggs, M.I., Thompson, G.A. Plant J. (1997) [Pubmed]
  7. Galectin-1 influences migration of retinal pigment epithelial cells. Alge, C.S., Priglinger, S.G., Kook, D., Schmid, H., Haritoglou, C., Welge-Lussen, U., Kampik, A. Invest. Ophthalmol. Vis. Sci. (2006) [Pubmed]
  8. Increased episomal replication accounts for the high rate of adaptive mutation in recD mutants of Escherichia coli. Foster, P.L., Rosche, W.A. Genetics (1999) [Pubmed]
  9. Detergent-mediated reconstitution of membrane proteins. Knol, J., Sjollema, K., Poolman, B. Biochemistry (1998) [Pubmed]
  10. Improved lysis of group N streptococci for isolation and rapid characterization of plasmid deoxyribonucleic acid. Klaenhammer, T.R., McKay, L.L., Baldwin, K.A. Appl. Environ. Microbiol. (1978) [Pubmed]
  11. Regulated expression of the diphtheria toxin A gene in human glioma cells using prokaryotic transcriptional control elements. Paulus, W., Baur, I., Oberer, D.M., Breakefield, X.O., Reeves, S.A. J. Neurosurg. (1997) [Pubmed]
  12. Fluvastatin prevents renal injury and expression of lactin-like oxidized low-density lipoprotein receptor-1 in rabbits with hypercholesterolemia. Yu, Y.H., Wang, Y., Dong, B., Sun, S.Z., Chen, Y., Meng, X.H., Liu, Z.Z. Chin. Med. J. (2005) [Pubmed]
  13. Mutations affecting synthesis of beta-galactosidase activity in the yeast Kluyveromyces lactis. Sheetz, R.M., Dickson, R.C. Genetics (1980) [Pubmed]
  14. Pathways for homologous recombination between chromosomal direct repeats in Salmonella typhimurium. Galitski, T., Roth, J.R. Genetics (1997) [Pubmed]
  15. An efficient synthesis of novel carbocyclic nucleosides with use of ring-closing metathesis from D-lactose. Hong, J.H., Shim, M.J., Ro, B.O., Ko, O.H. J. Org. Chem. (2002) [Pubmed]
  16. Cell aggregation of the marine sponge Geodia cydonium. Identification of lectin-producing cells. Müller, W.E., Zahn, R.K., Müller, I., Kurelec, B., Uhlenbruck, G., Vaith, P. Eur. J. Cell Biol. (1981) [Pubmed]
  17. Stimulation by colostrum or mature milk of gastrointestinal tissue development in newborn pigs. Simmen, F.A., Cera, K.R., Mahan, D.C. J. Anim. Sci. (1990) [Pubmed]
  18. EDRF release from canine coronary artery by lectins. Kleha, J.F., Devesly, P., Johns, A. Br. J. Pharmacol. (1993) [Pubmed]
  19. Small intestine epithelial barrier function is compromised in pigs with low feed intake at weaning. Spreeuwenberg, M.A., Verdonk, J.M., Gaskins, H.R., Verstegen, M.W. J. Nutr. (2001) [Pubmed]
  20. Isolation and characterization of a galactose-specific carbohydrate binding protein from human lymphoblastic cells. Baum, L.G., Cresswell, P. Biochem. Biophys. Res. Commun. (1990) [Pubmed]
  21. Antibody-independent classical complement pathway activation and homologous C3 deposition in xeroderma pigmentosum cell lines. Kurita, M., Matsumoto, M., Tsuji, S., Kawakami, M., Suzuki, Y., Hayashi, H., Toyoshima, K., Seya, T. Clin. Exp. Immunol. (1999) [Pubmed]
  22. Two different mechanisms for urea action at the LAC and TNA operons in Escherichia coli. Blazy, B., Ullmann, A. Mol. Gen. Genet. (1990) [Pubmed]
  23. The solution structure of Lac repressor headpiece 62 complexed to a symmetrical lac operator. Spronk, C.A., Bonvin, A.M., Radha, P.K., Melacini, G., Boelens, R., Kaptein, R. Structure (1999) [Pubmed]
  24. A tightly regulated expression system in Escherichia coli with SP6 RNA polymerase. Sagawa, H., Ohshima, A., Kato, I. Gene (1996) [Pubmed]
  25. Altered mRNA metabolism in ribonuclease III-deficient strains of Escherichia coli. Talkad, V., Achord, D., Kennell, D. J. Bacteriol. (1978) [Pubmed]
  26. The -45 region of the Escherichia coli lac promoter: CAP-dependent and CAP-independent transcription. Czarniecki, D., Noel, R.J., Reznikoff, W.S. J. Bacteriol. (1997) [Pubmed]
  27. Effect of alcohols on lactose solubility. Majd, F., Nickerson, T.A. J. Dairy Sci. (1976) [Pubmed]
  28. Transport regulation of recombinant gene expression in E. coli and B. subtilis. Boyer, J.D., Vieth, W.R., Bailey, K., Pedersen, H. Biotechnology advances. (1992) [Pubmed]
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