scholarly journals MODIFICATION OF THE GELATIN SUBSTRATE PROCEDURE FOR DEMONSTRATION OF ACROSOMAL PROTEOLYTIC ACTIVITY

1972 ◽  
Vol 20 (7) ◽  
pp. 499-506 ◽  
Author(s):  
ARTHUR PENN ◽  
BARTON L. GLEDHILL ◽  
ZBIGNIEW DARŻYNKIEWICZ

In situ proteolytic activity in the heads of sperm of seven mammalian species has been demonstrated using autoradiographic film as a gelatin substrate. The film is first exposed and processed and then coated with the sperm sample. Proteolytic activity is monitored by following the appearance of "halos," which are areas of gelatin digestion and are found to surround the heads of reacting sperm. The proteolytic factor appears to be released from the acrosome and may be the protease with trypsin-like activity that has been found associated with the acrosome in biochemical studies. l-Chloro-3-tosylamido-7-amino-2-heptanone and diisopropyl fluorophosphate, both of which inhibit trypsin activity, apparently interact with a substance released from the acrosome but do not interfere with the formation of halos. Sperm treated with trichloroacetic acid, urea or formalin do not form halos.

Open Biology ◽  
2015 ◽  
Vol 5 (8) ◽  
pp. 150080 ◽  
Author(s):  
Catherine E. Au ◽  
Louis Hermo ◽  
Elliot Byrne ◽  
Jeffrey Smirle ◽  
Ali Fazel ◽  
...  

Discovered in 1909 by Retzius and described mainly by morphology, the cytoplasmic droplet of sperm (renamed here the Hermes body) is conserved among all mammalian species but largely undefined at the molecular level. Tandem mass spectrometry of the isolated Hermes body from rat epididymal sperm characterized 1511 proteins, 43 of which were localized to the structure in situ by light microscopy and two by quantitative electron microscopy localization. Glucose transporter 3 (GLUT-3) glycolytic enzymes, selected membrane traffic and cytoskeletal proteins were highly abundant and concentrated in the Hermes body. By electron microscope gold antibody labelling, the Golgi trafficking protein TMED7/p27 localized to unstacked flattened cisternae of the Hermes body, as did GLUT-3, the most abundant protein. Its biogenesis was deduced through the mapping of protein expression for all 43 proteins during male germ cell differentiation in the testis. It is at the terminal step 19 of spermiogenesis that the 43 characteristic proteins accumulated in the nascent Hermes body.


Genome ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 138-142 ◽  
Author(s):  
Michael S. Zwick ◽  
Robert E. Hanson ◽  
M. Nurul Islam-Faridi ◽  
David M. Stelly ◽  
Rod A. Wing ◽  
...  

In situ hybridization (ISH) for the detection of single- or low-copy sequences, particularly large DNA fragments cloned into YAC or BAC vectors, generally requires the suppression or "blocking" of highly-repetitive DNAs. C0t-1 DNA is enriched for repetitive DNA elements, high or moderate in copy number, and can therefore be used more effectively than total genomic DNA to prehybridize and competitively hybridize repetitive elements that would otherwise cause nonspecific hybridization. C0t-1 DNAs from several mammalian species are commercially available, however, none is currently available for plants to the best of our knowledge. We have developed a simple 1-day procedure to generate C0t-1 DNA without the use of specialized equipment.Key words: C0t-1 DNA, in situ hybridization, BACs, plants.


1979 ◽  
Author(s):  
W.E. Laug

Cloned endothelial cells obtained from the aorta of 1-2 day old calves produced high fibrinolytic activity, which was 90% dependent upon the presence of plasminogen when grown on 125 I fibrin coated dishes. High plasminogen-dependent proteolytic activity was also demonstrated in the cell lysate and in the culture medium of the cells. The production and secretion of this prtitease were found to increase during the log phase of cell growth and to reach a maximum at con fluency. Thereafter they remained constantly high. This protease, partially purified from the culture medium of confluent endothelial cell cultures, is aiginine specific and activates plasminogen by piOteolytic cleavage to plasmin. Its proteolytic activity which is highest in the pH range of 7.5 to 8.0 is irreversibly inhibited by diisopropyl fluorophosphate, suggesting that it is a serine protease. The molecular weight of this protease is approximately S2000.


1988 ◽  
Vol 46 (4) ◽  
pp. 359-372
Author(s):  
Yoshihiro KADOWAKI ◽  
Tetsuro OHTA ◽  
Nobuo HOTOKEBUCHI ◽  
Sadatoshi KIMOTO ◽  
Masao HARUNA ◽  
...  

1994 ◽  
Vol 67 (4) ◽  
pp. 567-581 ◽  
Author(s):  
G. K. Dhaliwal ◽  
G. J. Wilson

Abstract Iodine index is used in the rubber industry to measure the unsaturation of butyl polymers. The procedure involves a complex mixture of iodine, mercuric acetate, and trichloroacetic acid (TCAA), and requires an empirical calibration to convert the iodine index to the degree of unsaturation. In this paper, the chemistry of the iodine index test is discussed and, the factors affecting the measurement, are detailed. Acetyl hypoiodite formed in situ by the reaction of I2 and Hg(OAc)2 is postulated to be the reactive species which iodinates the unsaturation in butyl rubber. Mercuric acetate is not a catalyst, as usually believed, but is consumed in stoichiometric amounts. Hence, care has to be exercised not to use too little of the mercuric acetate when determining the iodine index of polymers with high levels of unsaturation. A large excess of mercuric acetate must also be avoided, as it may form complexes with iodine and, thereby, lower the effective concentrations of both the reactive reagents.


Endocrinology ◽  
2008 ◽  
Vol 149 (5) ◽  
pp. 2467-2476 ◽  
Author(s):  
Shinji Kanda ◽  
Yasuhisa Akazome ◽  
Takuya Matsunaga ◽  
Naoyuki Yamamoto ◽  
Shunji Yamada ◽  
...  

Recently, a novel physiologically active peptide, kisspeptin (metastin), has been reported to facilitate sexual maturation and ovulation by directly stimulating GnRH neurons in several mammalian species. Despite its importance in the neuroendocrine regulation of reproduction, kisspeptin neurons have only been studied in mammals, and there has been no report on the kisspeptin or kisspeptin neuronal systems in nonmammalian vertebrates. We used medaka for the initial identification of the KiSS-1 gene and the anatomical distribution of KiSS-1 mRNA expressing neurons (KiSS-1 neurons) in the brain of nonmammalian species. In situ hybridization for the medaka KiSS-1 gene cloned here proved that two kisspeptin neuronal populations are localized in the hypothalamic nuclei, the nucleus posterioris periventricularis and the nucleus ventral tuberis (NVT). Furthermore, NVT KiSS-1 neurons were sexually dimorphic in number (male neurons ≫ female neurons) under the breeding conditions. We also found that the number of KiSS-1 neurons in the NVT but not that in the nucleus posterioris periventricularis was positively regulated by ovarian estrogens. The fact that there were clear differences in the number of NVT KiSS-1 neurons between the fish under the breeding and nonbreeding conditions strongly suggests that the steroid-sensitive changes in the KiSS-1 mRNA expression in the NVT occur physiologically, according to the changes in the reproductive state. From the present results, we conclude that the medaka KiSS-1 neuronal system is involved in the central regulation of reproductive functions, and, given many experimental advantages, the medaka brain may serve as a good model system to study its physiology.


1982 ◽  
Vol 202 (1) ◽  
pp. 47-51 ◽  
Author(s):  
L Lavie ◽  
A Z Reznick ◽  
D Gershon

Liver protein-degradation rates were determined in young and old C57B1 mice by the method of Swick & Ip [(1974) J. Biol. Chem. 249, 6836-6841]. The results indicated a marked age-related increase in the half-lives of short-lived proteins in the nuclear, mitochondrial, lysosomal and 100000 g-supernatant cellular fractions and in total trichloroacetic acid-precipitable proteins. The efficiency of the degradation system in removing aberrant proteins from livers of young and old mice was tested. The time required for 50% disappearance of puromycinyl-peptides changed from about 20 min in 6-month-old mice to approx. 150 min in 24-month-old animals. These findings suggest that in old animals the proteolytic activity involved in degradation of aberrant proteins, and presumably of "native proteins, is markedly defective.


1988 ◽  
Vol 46 (4) ◽  
pp. 359-372 ◽  
Author(s):  
Yoshihiro KADOWAKI ◽  
Tetsuro OHTA ◽  
Nobuo HOTOKEBUCHI ◽  
Sadatoshi KIMOTO ◽  
Masao HARUNA ◽  
...  

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