scholarly journals Changes in Pectins in Apple Fruit during Development and Ripening

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 816A-816
Author(s):  
Jong-Pil Chun ◽  
Jae-Chang Lee ◽  
Yong-Soo Hwang
Keyword(s):  
Ion Exchange ◽  
Potential Role ◽  
Gel Filtration ◽  
Apple Fruit ◽  
Fruit Softening ◽  
Pectin Degradation ◽  
Degree Of Esterification ◽  
Fruit Development And Ripening ◽  
Chromatographic Evidence

Pectins isolated from three cultivars with different maturity were compared to find a potential role of pectin modification on the fruit softening during fruit development and ripening. There was an increase of total pectins in developing fruit and no significant decrease of pectins was confirmed even after storage in `Tusgaru' (30 days) and `Fuji' (120 days), whereas soluble pectins, except NaOH-soluble ones, gradually increased in all cultivars. Gel-filtration profile and ion exchange chromatographic evidence of soluble pectins revealed that pectin degradation in apple fruit may not be associated with softening. However, a degree of esterification probably has an important role on softening of fruits. Further results will be discussed in the presentation.

Purification and Thermodynamic Characteristics of an Exo-Polygalacturonase from Trichoderma Pseudokoningii

2020 ◽  
Vol 42 (5) ◽  
pp. 767-767
Author(s):  
Wesam H Abdulaal and Yaaser Q Almulaiky Wesam H Abdulaal and Yaaser Q Almulaiky
Keyword(s):  
Food Industry ◽  
Potential Role ◽  
Fruit Juice ◽  
Gel Filtration ◽  
Thermodynamic Characteristics ◽  
Orange Peel ◽  
Sds Page ◽  
Trichoderma Pseudokoningii ◽  
Km Value

Polygalacturonases (PGs) are necessary to degrade the insoluble viscous pectin components during the clarification process of fruit juice and are produced by some plants and various microbes, such as bacteria, yeasts and fungi. In this study, an exo-polygalacturonase (exo-PGP4a) was purified from T. Pseudokoningii using DEAE-Sepharose and Sephacryl S-200 columns. We show that the enzyme produced in this study by solid-state fermentation of citrus Orange peel was purified 20-fold with 12.8% recovery. The apparent molecular mass of the enzyme was determined to be 25 kDa using gel filtration and SDS-PAGE. The optimum temperature and pH of the exo-PGP4a were 45and#176;C and 6, respectively. The exo-PGP4a showed half-lives of 50.95 and 21.32 min at 55 and 75and#176;C, respectively. The activation energy for denaturation (Ea*) was 42.596 kJ/mol. The Km value of the enzyme for PGA hydrolysis was 2 mg/ml, and the Vmax was 3.27 and#181;mol min-1 mg-1. Several metal cations, such as Cu2+and Zn2+, were found to enhance the enzymatic activity of the exo-PGP4a, while Pb2+, Ca2+, Ni2+, Cd2+, Co2+ and Hg2+ ions were found to be inhibitory. In this study, we suggest the exo-polygalacturonase has potential role of the clarification of Orange, Apple, Grape, and Peach juices in the food industry.

scholarly journals Partial purification and characterization of a peroxidase activity from human placenta

1990 ◽  
Vol 268 (3) ◽  
pp. 739-743 ◽  
Author(s):  
J L Nelson ◽  
A P Kulkarni
Keyword(s):  
Peroxidase Activity ◽  
Potential Role ◽  
Gel Filtration ◽  
Partial Purification ◽  
Human Haemoglobin ◽  
Prostaglandin Synthase ◽  
Membrane Bound ◽  
Cytochrome P 450

Peroxidases can metabolize a variety of xenobiotics to reactive intermediates capable of binding to protein or DNA. The potential role of these enzymes in fetotoxicity has not been explored. In this study, the presence of peroxidase activity was observed in human term and pre-term placenta. Human term placental peroxidase activity (HTPP) was partially purified by concanavalin A affinity chromatography from CaCl2 extracts of the particulate fraction. HTPP appears to be a membrane-bound glycoprotein. Arachidonic acid-dependent oxidation of guaiacol was not observed, suggesting that the peroxidase activity was not due to prostaglandin synthase. Moreover, HTPP preparations were devoid of catalase and spectrally dissimilar from human haemoglobin, cytochrome P-450, eosinophil peroxidase and myloperoxidase, suggesting an endogenous origin. An Mr of approx. 119,000 was determined for HTPP by gel filtration. Cathodic slab-PAGE of cetyltrialkylammonium bromide-solubilized HTPP yielded two peroxidase-staining bands.

scholarly journals FLORAL-DERIVED VOLATILE COMPOUNDS: A ROLE IN POLLINATION?

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1128d-1128
Author(s):  
Douglas D. Archbold ◽  
Thomas R. Hamilton-Kemp ◽  
John H. Loughrin
Keyword(s):  
Volatile Compounds ◽  
Pollen Germination ◽  
Potential Role ◽  
Apple Fruit ◽  
Capillary Gc ◽  
Full Bloom ◽  
Percent Germination

Volatile compounds, commonly produced by flowers during bloom, have been described as insect attractants. Some of these compounds stimulate Pinus pollen germination in vitro (French et al., 1979, J. Agric. Fd. Chem., 27184-187), suggesting that such compounds may do the same in vivo. Red Delicious apple pollen was germinated on agar in a simple, enclosed in vitro bioassay system in the presence of a number of plant tissues, including apple, tomato, and chrysanthemum leaves, apple flowers, rose petals, and apple fruit slices. These tissues represent a diversity of types of volatile compounds, Pollen germination was recorded by microphotography after 1 and 2 hours, and percent germination was determined. Although stimulation of germination was not observed, macerated tomato leaves inhibited it. To determine if the volatile characteristics of cultivars differ, flowers of Red Delicious and Golden Delicious apple were harvested at full bloom. Their volatiles were collected, identified, and quantitated by capillary GC-MS. Among 8 major compounds common in the two cultivars, several quantitative differences were observed. These results will be discussed in relation to the potential role of volatiles in pollen germination.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

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