The Bakerian Lecture: Molecular structure in the polysaccharide group

1959 ◽  
Vol 252 (1270) ◽  
pp. 287-312 ◽  
Keyword(s):  
Molecular Structure ◽  
Fine Structure ◽  
Biological Function ◽  
Structural Features ◽  
Molecular Structures ◽  
Molecular Architecture ◽  
Considerable Time ◽  
General Acceptance ◽  
Naturally Occurring ◽  
Precise Knowledge

It has been clear for some considerable time that a more precise knowledge of the molecular structure of the polysaccharides is needed for the solution of many problems in biology and medicine. This was emphasized by Sir Norman Haworth in the Bakerian Lecture delivered in 1944, when he reviewed the position then reached concerning the structure, biological function and synthesis of typical polysaccharides. In this connexion it is of interest to recall that by 1944 the view that naturally occurring colloidal substances such as starch and cellulose possessed molecular structures held together by normal co-valent bonds had received general acceptance for less than 20 years. Furthermore, the evidence for the main structural features of the polysaccharides had been acquired by difficult and laborious experimental methods which normally involved the manipulation of large quantities of material. Some idea of the general molecular architecture of many polysaccharides had been gained, but the methods then available were not capable of delving much deeper into the detailed structural features. This fine structure is nevertheless of particular importance, since the presence of irregular features in the molecule, even in slight degree, may alter quite markedly the behaviour of these high polymers. It will be readily understood also that the fine structure of these macromolecules is a matter of great moment in enzymology.

scholarly journals Interactive association between processing induced molecular structure changes and nutrient delivery on a molecular basis, revealed by cutting-edge vibrational biomolecular spectroscopy

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Aya Ismael ◽  
Victor Hugo Guevara-Oquendo ◽  
Basim Refat ◽  
Peiqiang Yu
Keyword(s):  
Molecular Structure ◽  
Molecular Spectroscopy ◽  
Degradation Kinetics ◽  
Structural Features ◽  
Molecular Structures ◽  
Non Invasive ◽  
Structure Changes ◽  
Ft Ir ◽  
Α Helix ◽  
Β Sheet

Abstract Background This study was conducted to determine protein molecular structure profiles and quantify the relationship between protein structural features and protein metabolism and bioavailability of blend pelleted products (BPP) based on co-products (canola or carinata) from processing with different proportions of pulse pea screenings and lignosulfonate chemical compound. Method The protein molecular structures were determined using the non-invasive advanced vibrational molecular spectroscopy (ATR-FT/IR) in terms of chemical structure and biofunctional groups of amides (I and II), α-helix and β-sheet. Results The results showed that increasing the level of the co-products in BPP significantly increased the spectral intensity of the amide area and amide height. The products exhibited similar protein secondary α-helix to β-sheet ratio. The protein molecular structure profiles (amides I and II, α-helix to β-sheet) were highly associated with protein degradation kinetics and intestinal digestion. In conclusion, the non-invasive vibrational molecular spectroscopy (ATR-FT/IR) could be used to detect inherent structural make-up characteristics in BPP. Conclusion The molecular structural features related to protein biopolymer were highly associated with protein utilization and metabolism.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Molecular architecture and functions of the neuronal cytoskeleton

1990 ◽  
Vol 48 (3) ◽  
pp. 2-3
Author(s):  
Nobutaka Hirokawa
Keyword(s):  
Major Elements ◽  
Molecular Structures ◽  
Organelle Transport ◽  
Molecular Architecture ◽  
Neuronal Morphogenesis ◽  
Microtubule Associated Proteins ◽  
Associated Proteins ◽  
And Function ◽  
Small Clusters

In this symposium I will present our studies about the molecular architecture and function of the cytomatrix of the nerve cells. The nerve cell is a highly polarized cell composed of highly branched dendrites, cell body, and a single long axon along the direction of the impulse propagation. Each part of the neuron takes characteristic shapes for which the cytoskeleton provides the framework. The neuronal cytoskeletons play important roles on neuronal morphogenesis, organelle transport and the synaptic transmission. In the axon neurofilaments (NF) form dense arrays, while microtubules (MT) are arranged as small clusters among the NFs. On the other hand, MTs are distributed uniformly, whereas NFs tend to run solitarily or form small fascicles in the dendrites Quick freeze deep etch electron microscopy revealed various kinds of strands among MTs, NFs and membranous organelles (MO). These structures form major elements of the cytomatrix in the neuron. To investigate molecular nature and function of these filaments first we studied molecular structures of microtubule associated proteins (MAP1A, MAP1B, MAP2, MAP2C and tau), and microtubules reconstituted from MAPs and tubulin in vitro. These MAPs were all fibrous molecules with different length and formed arm like projections from the microtubule surface.

scholarly journals Resolving Entangled JH-H-Coupling Patterns for Steroidal Structure Determinations by NMR Spectroscopy

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2643
Author(s):  
Danni Wu ◽  
Kathleen Joyce Carillo ◽  
Jiun-Jie Shie ◽  
Steve S.-F. Yu ◽  
Der-Lii M. Tzou
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr Spectroscopy ◽  
Chemical Shifts ◽  
Atomic Level ◽  
Molecular Structures ◽  
Naturally Occurring ◽  
Structure Determinations ◽  
Ligand Interactions ◽  
Synthetic Steroids ◽  
The Individual

For decades, high-resolution 1H NMR spectroscopy has been routinely utilized to analyze both naturally occurring steroid hormones and synthetic steroids, which play important roles in regulating physiological functions in humans. Because the 1H signals are inevitably superimposed and entangled with various JH–H splitting patterns, such that the individual 1H chemical shift and associated JH–H coupling identities are hardly resolved. Given this, applications of thess information for elucidating steroidal molecular structures and steroid/ligand interactions at the atomic level were largely restricted. To overcome, we devoted to unraveling the entangled JH–H splitting patterns of two similar steroidal compounds having fully unsaturated protons, i.e., androstanolone and epiandrosterone (denoted as 1 and 2, respectively), in which only hydroxyl and ketone substituents attached to C3 and C17 were interchanged. Here we demonstrated that the JH–H values deduced from 1 and 2 are universal and applicable to other steroids, such as testosterone, 3β, 21-dihydroxygregna-5-en-20-one, prednisolone, and estradiol. On the other hand, the 1H chemical shifts may deviate substantially from sample to sample. In this communication, we propose a simple but novel scheme for resolving the complicate JH–H splitting patterns and 1H chemical shifts, aiming for steroidal structure determinations.

scholarly journals Exciton Fine-Structure Splitting in Self-Assembled Lateral InAs/GaAs Quantum-Dot Molecular Structures

ACS Nano ◽  
2015 ◽  
Vol 9 (6) ◽  
pp. 5741-5749 ◽  
Author(s):  
Stanislav Fillipov ◽  
Yuttapoom Puttisong ◽  
Yuqing Huang ◽  
Irina A. Buyanova ◽  
Suwaree Suraprapapich ◽  
...  
Keyword(s):  
Fine Structure ◽  
Quantum Dot ◽  
Molecular Structures ◽  
Fine Structure Splitting ◽  
Structure Splitting ◽  
Self Assembled ◽  
Gaas Quantum Dot

Metaphoric chains

2021 ◽  
Vol 19 (2) ◽  
pp. 273-298
Author(s):  
Sakineh Navidi-Baghi ◽  
Ali Izanloo ◽  
Alireza Qaeminia ◽  
Alireza Azad
Keyword(s):  
Molecular Structure ◽  
Conceptual Metaphor ◽  
Previous Literature ◽  
Molecular Structures ◽  
Conceptual Metaphor Theory ◽  
Metaphor Theory ◽  
Different Types ◽  
New Form

Abstract The molecular structure of a complex metaphor comprises two or more atomic metaphorical parts, known as primary metaphors. In the same way, several molecular structures of metaphors may combine and form a mixture, known as mixed metaphors. In this study, different types of metaphoric integrations are reviewed and illustrated in figures to facilitate understanding the phenomena. Above all, we introduce double-ground metaphoric chain, a new form of metaphoric integration that has not been identified in the previous literature. Also, a distinction is made between single-ground and double-ground metaphoric chains. In the former, which has already been introduced, two basic metaphors are chained with the same form and have the same ground, while the latter includes two chained metaphors, one main metaphor plus a supportive one, with different grounds. In this analysis, we benefited from Conceptual Metaphor Theory (CMT) to analyse double-ground metaphoric chains. This study suggests that each metaphoric integration leads to a multifaceted conceptualization, in which each facet is related to one of the constituent micro-metaphors.

scholarly journals Insights into the Intrinsic Factors Affecting the NIR Reflectance Based on Rylene Diimide Molecules

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5269
Author(s):  
Weili Zeng ◽  
Yujie Song ◽  
Jianning Zhang ◽  
Hong Chen ◽  
Ming Liu ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Molecular Structures ◽  
Heat Radiation ◽  
Clear Understanding ◽  
Factors Affecting ◽  
Intrinsic Factors ◽  
Alkyl Groups ◽  
Amine Groups

A clear understanding of the relationships between molecular structure and NIR reflectance (700–2500 nm) behavior is important and highly desirable for developing appropriate NIR-reflective materials to combat NIR heat radiation from sunlight. In this research, three groups of imide-based compounds have been adopted to investigate the influence of the intrinsic molecular structures on the NIR-reflective properties. It is found out that for the compounds with alkyl groups, the NIR reflectance will increase as the degree of the conjugated backbone increases, especially for the reflectance from 1750 nm to 2500 nm. In addition, despite that the alkyl or amine groups deteriorate the NIR reflectance, the NIR reflectance varies within a certain interval and the isomers with branched alkyl groups show identical or smaller NIR reflectance than those of isomers with linear alkyl groups. For different compounds, crystallinity seems to almost have no relationship with their NIR reflectance.

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