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Titolo:
Lactoferrin-melanin interaction and its possible implications in melanin polymerization: Crystal structure of the complex formed between mare lactoferrin and melanin monomers at 2.7-angstrom resolution
Autore:
Sharma, AK; Kumar, S; Sharma, V; Nagpal, A; Singh, N; Tamboli, I; Mani, I; Raman, G; Singh, TP;
Indirizzi:
All India Inst Med Sci, Dept Biophys, New Delhi 110029, India All India Inst Med Sci New Delhi India 110029 s, New Delhi 110029, India Hindustan Lever Res Ctr, Bangalore, Karnataka, India Hindustan Lever Res Ctr Bangalore Karnataka India lore, Karnataka, India
Titolo Testata:
PROTEINS-STRUCTURE FUNCTION AND GENETICS
fascicolo: 3, volume: 45, anno: 2001,
pagine: 229 - 236
SICI:
0887-3585(20011115)45:3<229:LIAIPI>2.0.ZU;2-M
Fonte:
ISI
Lingua:
ENG
Soggetto:
ANGSTROM RESOLUTION; 3-DIMENSIONAL STRUCTURE; PLASMA; REFINEMENT; OVOTRANSFERRIN;
Keywords:
melanin; lactoferrin; complex; crystal structure; polymerization; indole-5,6-quinone; dihydroxy phenylalanine;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
33
Recensione:
Indirizzi per estratti:
Indirizzo: Singh, TP All India Inst Med Sci, Dept Biophys, New Delhi 110029, India All India Inst Med Sci New Delhi India 110029 hi 110029, India
Citazione:
A.K. Sharma et al., "Lactoferrin-melanin interaction and its possible implications in melanin polymerization: Crystal structure of the complex formed between mare lactoferrin and melanin monomers at 2.7-angstrom resolution", PROTEINS, 45(3), 2001, pp. 229-236

Abstract

The concentration of melanin determines the intensity of colors of the skin and hair of animals. Melanin pigments are tyrosine-based polymers formed in melanocytes within specialized organelles called melanosomes. In order to understand the mechanism of melanin polymerization, lactoferrin, a basic protein with a pl value of 9.0, has been used to produce melanin. Lactoferrin is a monomeric iron-binding protein with a molecular weight of 80 kDa. The crystals of lactoferrin were soaked in a solution containing dihydroxyphenylalanine (DOPA) and tyrosinase enzyme. These crystals were used for X-ray intensity data collection. The intensity data were collected to 2.7-Angstrom resolution to an overall completeness of 91% with an R-sym of 0.071. The crystals belong to orthorhombic space group P2(1)2(1)2(1) with cell dimensions: a = 85.0 Angstrom, b = 99.8 Angstrom, c = 103.4 Angstrom. The structure was determined by molecular replacement method, using the model of diferric mare lactoferrin, and refined to an R-factor 0.215 (R-free = 0.287) for all the data to 2.7-Angstrom resolution. The final model comprises 5,281 protein atoms from 689 amino acids, 2Fe(3+), 2CO(3)(2-) ions, 2 indole-5,6-quinone molecules (IQ), and 73 water molecules. Two IQ molecules, one in each lobe, bind to lactoferrin. In the C-lobe, the IQ binds in the iron-binding cleft, whereas in the N-lobe, it is located in the side pocket between two a-helices, filled with solvent molecules in the native iron-saturated mare lactoferrin. The IQ molecules interact with protein molecule mainly through glutamic acid in both lobes, without significant perturbation to the protein structure. The orientation of N- and C-lobes in the present structureis similar to that observed in the native iron-saturated protein. However,as a result of the binding of IQ molecules, the orientations of the domains N1, N2 and C1, C2 in the two cases differ slightly. (C) 2001 Wiley-Liss,Inc.

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Documento generato il 14/07/20 alle ore 06:23:17