lipoteichoic-acid and lauric-acid

Short peptidoglycan recognition protein (PGRP-S) is a member of the mammalian innate immune system. PGRP-S from Camelus dromedarius (CPGRP-S) has been shown to bind to lipopolysaccharide (LPS), lipoteichoic acid (LTA) and peptidoglycan (PGN). Its structure consists of four molecules A, B, C and D with ligand binding clefts situated at A-B and C-D contacts. It has been shown that LPS, LTA and PGN bind to CPGRP-S at C-D contact. The cleft at the A-B contact indicated features that suggested a possible binding of fatty acids including mycolic acid of Mycobacterium tuberculosis. Therefore, binding studies of CPGRP-S were carried out with fatty acids, butyric acid, lauric acid, myristic acid, stearic acid and mycolic acid which showed affinities in the range of 10(-5) to 10(-8) M. Structure determinations of the complexes of CPGRP-S with above fatty acids showed that they bound to CPGRP-S in the cleft at the A-B contact. The flow cytometric studies showed that mycolic acid induced the production of pro-inflammatory cytokines, TNF-α and IFN-γ by CD3+ T cells. The concentrations of cytokines increased considerably with increasing concentrations of mycolic acid. However, their levels decreased substantially on adding CPGRP-S.

Topics: Amino Acid Sequence; Animals; Binding Sites; Butyric Acid; Camelus; Carrier Proteins; Crystallography, X-Ray; Female; Humans; Interferon-gamma; Kinetics; Lauric Acids; Lipopolysaccharides; Mammary Glands, Animal; Models, Molecular; Molecular Sequence Data; Mycobacterium tuberculosis; Mycolic Acids; Myristic Acid; Peptidoglycan; Protein Binding; Protein Structure, Tertiary; Stearic Acids; T-Lymphocytes; Teichoic Acids; Tumor Necrosis Factor-alpha