Hydroxycinnamic acid modified xylan side chains and their cross‐linking products in rice cell walls are reduced in the Xylosyl arabinosyl substitution of xylan 1 mutant

The amino acid sequence of the peptide moiety of the mureins of Lactobacillus coryniformis and Lactobacillus cellobiosus cell walls was determined. This was accomplished by the identification of peptides obtained after partial hydrolysis of purified cell walls and by the identification of UDP-activated murein precursors accumulated by ᴅ-cycloserine inhibition. The amino acid sequence proved to be : ʟ-ala-ᴅ-glu-ʟ-lys-ᴅ-ala for L. coryniformis and L-ala-D-glu-L-orn-D-ala for L. cellobio-.D-asp D-aspsus. Aspartic acid is involved in the cross-linking of the mureins by forming a peptide bond with the C-terminal D-alanine of an adjacent muropeptide. Glutamic acid as well as aspartic acid are present as amides.

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California Date Varieties Have More Total Dietary Fibers Both Soluble and Insoluble (P06-120-19)

Current Developments in Nutrition ◽

10.1093/cdn/nzz031.p06-120-19 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Author(s):

Charlene Rainey ◽

Emilia Alfaro-Viquez ◽

Christian Krueger ◽

Jess Reed

Keyword(s):

Cell Walls ◽

Intestinal Microflora ◽

Elongation Factor ◽

Cross Linking ◽

Intestinal Epithelial ◽

Equal Part ◽

Dietary Fibers ◽

Digestive Process ◽

Funding Sources ◽

Mass Spec

Abstract Objectives The objective of this study was to analyze the TDF, soluble and insoluble fibers, comparing the results with the new analytical method and for minerals associated with fiber. This is the first reporting of date fibers comparing the methods of analysis. Methods TDF methods AOAC 2011.25 methods were updated using Rapid Integrated (RI), a rapid digestion of 4 hours closely resembling human digestion. Testing was conducted at Medallion in Minneapolis, Minnesota. Equal part deglet noor and medjool varieties were analyzed by both methods. Minerals were tested by ICP Mass Spec Eurofin, Wisconsin. Results TDF for the new RI method yielded higher results than AOAC 2011.25 (8.7 mg vs 8.0 mg/100 g). Both soluble and insoluble are considered bioavailable, as they interact with the gut intestinal epithelial and intestinal microflora in the digestive process. Most of date TDF are insoluble 64% and 34% are soluble. The 0.7 mg increase in TDF comes mostly as Soluble. The new RI method and the AOAC 2011.25 Soluble were (3.1 vs 2.5 mg/100 g) respectively. The Insoluble Dietary Fibers showed a slight increase of (0.1 mg/100 g) with the new method at (5.6 vs 5.5 mg/100 g.) Calcium (62.5 mg/100 grams.) indicates cell wall pectin cross-linking. Selenium was (4.94 mg/100 g) and upregulates genes involved in building cell walls. Boron was (0.942 mg/100 g) which is involved with the elongation factor for cell walls. Conclusions The new increased values of date Dietary Fibers and minerals linked to fiber show dates as a positive inclusion in diets. Dates have been shown to have many health benefits including decrease the risk of colon cancer. Funding Sources California Date Commission, Indio, California, provided an unrestricted grant to fund this research.

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Remodeling of Cross-bridges Controls Peptidoglycan Cross-linking Levels in Bacterial Cell Walls

ACS Chemical Biology ◽

10.1021/acschembio.0c00002 ◽

2020 ◽

Vol 15 (5) ◽

pp. 1261-1267 ◽

Cited By ~ 5

Author(s):

Alexis J. Apostolos ◽

Sean E. Pidgeon ◽

Marcos M. Pires

Keyword(s):

Bacterial Cell ◽

Cell Walls ◽

Cross Linking ◽

Bacterial Cell Walls ◽

Cross Bridges

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Self-generated covalent cross-links in the cell-surface adhesins of Gram-positive bacteria

Biochemical Society Transactions ◽

10.1042/bst20150066 ◽

2015 ◽

Vol 43 (5) ◽

pp. 787-794 ◽

Cited By ~ 13

Author(s):

Edward N. Baker ◽

Christopher J. Squire ◽

Paul G. Young

Keyword(s):

Cell Surface ◽

Mechanical Strength ◽

Cell Walls ◽

Side Chains ◽

Structural Studies ◽

Gram Positive Bacteria ◽

Intramolecular Reactions ◽

Isopeptide Bonds ◽

Cross Links ◽

Surface Adhesins

The ability of bacteria to adhere to other cells or to surfaces depends on long, thin adhesive structures that are anchored to their cell walls. These structures include extended protein oligomers known as pili and single, multi-domain polypeptides, mostly based on multiple tandem Ig-like domains. Recent structural studies have revealed the widespread presence of covalent cross-links, not previously seen within proteins, which stabilize these domains. The cross-links discovered so far are either isopeptide bonds that link lysine side chains to the side chains of asparagine or aspartic acid residues or ester bonds between threonine and glutamine side chains. These bonds appear to be formed by spontaneous intramolecular reactions as the proteins fold and are strategically placed so as to impart considerable mechanical strength.

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Pectin Rhamnogalacturonan II: On the “Small Stem with Four Branches” in the Primary Cell Walls of Plants

International Journal of Carbohydrate Chemistry ◽

10.1155/2011/964521 ◽

2011 ◽

Vol 2011 ◽

pp. 1-11 ◽

Cited By ~ 17

Author(s):

Beda M. Yapo

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Vascular Plants ◽

Minor Component ◽

Primary Cell ◽

Side Chains ◽

Complex Cell ◽

Rhamnogalacturonan Ii ◽

Branching Point ◽

A Chain

Rhamnogalacturonan II (RG-II) is a type of block copolymer of complex pectins that represents a quantitatively minor component of the primary cell walls of land (vascular) plants. The structural composition of RG-II is almost totally sequenced and appears to be remarkably conserved in all tracheophytes so far examined. The backbone of RG-II, released from complex (cell wall) pectins by endo-polygalacturonase (Endo-PG) treatment, has been found to contain up to 15 (1→4)-linked-α-D-GalpA units, some of which carry four well-defined side chains, often referred to as A-, B-, C-, and D-side chains. Nevertheless, the relative locations on the backbone of these four branches, especially the A chain, remain to be ascertained. A combination of different data suggests that neither the terminal nonreducing GalA nor the contiguous GalA unit is likely to be the branching point of the A chain, but probably the ninth GalA residue from the reducing end, assuming a minimum backbone length of 11 (1→4)-linked-α-d-GalpA. The latest reports on RG-II are here highlighted, with a provided update for the macrostructure and array of functionalities.

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