Paneth cells at the base of small intestinal crypts of Lieberkühn secrete host defense peptides and proteins, including alpha-defensins, as mediators of innate immunity. Mouse Paneth cells also express alpha-defensin-related Defcr-rs genes that code for cysteine-rich sequence 4C (CRS4C) peptides that have a unique CPX triplet repeat motif. In ileitis-prone SAMP1/YitFc mice, Paneth cell levels of CRS4C mRNAs and peptides are induced more than a 1000-fold relative to non-prone strains as early as 4 weeks of age, with the mRNA and peptide levels highest in distal ileum and below detection in duodenum.
View Article and Find Full Text PDFActa Crystallogr D Biol Crystallogr
July 2007
A Bence Jones protein isolated in the early 1960s from a patient (initials KWR) suffering from plasma-cell dyscrasia was crystallized and its structure was analyzed in four different unit cells by X-ray diffraction. The final models of the molecule in all crystal forms were virtually the same, although the elbow angles relating the constant and variable domains of the Bence Jones dimers varied over a range of 10 degrees. The tetragonal form had an R factor of 22.
View Article and Find Full Text PDFActa Crystallogr Sect F Struct Biol Cryst Commun
January 2005
Four crystal forms have been grown and characterized by X-ray diffraction of a Bence-Jones protein collected from the urine of a multiple myeloma patient more than 40 years ago. Closely related tetragonal and orthorhombic forms belonging to space groups P4(3)2(1)2 and P2(1)2(1)2(1), with unit-cell parameters a = b = 68.7, c = 182.
View Article and Find Full Text PDFThe alpha-defensin antimicrobial peptide family is defined by a unique tridisulfide array. To test whether this invariant structural feature determines alpha-defensin bactericidal activity, mouse cryptdin-4 (Crp4) tertiary structure was disrupted by pairs of site-directed Ala for Cys substitutions. In a series of Crp4 disulfide variants whose cysteine connectivities were confirmed using NMR spectroscopy and mass spectrometry, mutagenesis did not induce loss of function.
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