Identification and Structural Characterization of Naturally-Occurring Broad-Spectrum Cyclic Antibiotics Isolated from Paenibacillus

Naturally occurring 2-hydroxy-1,4-naphthoquinones are well known to form readily stable complexes with transition metals. In this short communication we describe for the first time the synthesis and preliminary data about structural characterization of complexes between two naturally widespread 2-hydroxy-1,4-naphthoquinones, namely lapachol (1) and lawsone (2), with selected lanthanides like lanthanum, gadolinium, and ytterbium. When tested as cytotoxic compounds, such complexes exhibited an activity that was either higher or equal to that of the parent naphthoquinone.

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Characterization of two crystal forms of neutrophil cationic protein NP2, a naturally occurring broad-spectrum antimicrobial agent from leukocytes

Journal of Molecular Biology ◽

10.1016/0022-2836(84)90252-3 ◽

1984 ◽

Vol 178 (3) ◽

pp. 783-785 ◽

Cited By ~ 7

Author(s):

Edwin M. Westbrook ◽

Robert I. Lehrer ◽

Michael E. Selsted

Keyword(s):

Antimicrobial Agent ◽

Broad Spectrum ◽

Cationic Protein ◽

Crystal Forms ◽

Naturally Occurring

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The X-ray structure of human P-cadherin EC1-EC2 in a closed conformation provides insight into the type I cadherin dimerization pathway

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x15003878 ◽

2015 ◽

Vol 71 (4) ◽

pp. 371-380 ◽

Cited By ~ 6

Author(s):

Andrea Dalle Vedove ◽

Anna Paola Lucarelli ◽

Valentina Nardone ◽

Angelica Matino ◽

Emilio Parisini

Keyword(s):

Structural Characterization ◽

Adherens Junction ◽

Large Family ◽

Type I ◽

Calcium Dependent ◽

Closed Conformation ◽

Naturally Occurring ◽

Packing Arrangement

Cadherins are a large family of calcium-dependent proteins that mediate cellular adherens junction formation and tissue morphogenesis. To date, the most studied cadherins are those classified as classical, which are further divided into type I or type II depending on selected sequence features. Unlike other members of the classical cadherin family, a detailed structural characterization of P-cadherin has not yet been fully obtained. Here, the high-resolution crystal structure determination of the closed form of human P-cadherin EC1-EC2 is reported. The structure shows a novel, monomeric packing arrangement that provides a further snapshot in the yet-to-be-achieved complete description of the highly dynamic cadherin dimerization pathway. Moreover, this is the first multidomain cadherin fragment to be crystallized and structurally characterized in its closed conformation that does not carry any extra N-terminal residues before the naturally occurring aspartic acid at position 1. Finally, two clear alternate conformations are observed for the critical Trp2 residue, suggestive of a transient, metastable state. The P-cadherin structure and packing arrangement shown here provide new and valuable information towards the complete structural characterization of the still largely elusive cadherin dimerization pathway.

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Composition of Color Substances of Hevea Brasiliensis Natural Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3539403 ◽

2007 ◽

Vol 80 (2) ◽

pp. 212-230 ◽

Cited By ~ 4

Author(s):

Jitladda Sakdapipanich ◽

Kittipong Insom ◽

Nataphon Phupewkeaw

Keyword(s):

Fatty Acids ◽

High Resolution ◽

Natural Rubber ◽

Structural Characterization ◽

Unsaturated Fatty Acids ◽

Rubber Latex ◽

Naturally Occurring ◽

Bottom Fraction ◽

Light Color

Abstract It is accepted that NR gives naturally occurring color, which restrict many applications such as light-color products. Therefore, characterization of color substances presenting in NR is very useful to develop the certain methodology to eliminate them completely or partly from NR in the future. In this work, an attempt was made to purify and characterize the color substances extracted from various fractions of Hevea rubber latex by certain methods, using high-resolution structural characterization techniques. It was found that the content of color substances extracted from fresh latex (FL), rubber cream, bottom fraction (BF), Frey Wyssling (FW) particles and STR 20 were different. Based on the high-resolution spectroscopic analyzes, it was found that the color substances extracted from NR were composed of carotenoids, tocotrienol esters, fatty alcohol esters, tocotrienols, unsaturated fatty acids, fatty alcohols, diglyceride and monoglyceride. The results will be useful for rubber-technologist to identify the origin to make obnoxious color in natural rubber, especially in some applications which are restricted by such the color.

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