Determination of protein: A modification of the lowry method that gives a linear photometric response
TL;DR: Under the new conditions there is direct proportionality between absorbance at 650 nm and weight of protein within the range 15–110 μg.
About: This article is published in Analytical Biochemistry.The article was published on 1972-08-01. It has received 5177 citations till now. The article focuses on the topics: Lowry protein assay & Bovine serum albumin.
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TL;DR: Plasmid expression vectors have been constructed that direct the synthesis of foreign polypeptides in Escherichia coli as fusions with the C terminus of Sj26, a 26-kDa glutathione S-transferase (GST; EC 2.5.1.18) encoded by the parasitic helminth Schistosoma japonicum.
6,003 citations
TL;DR: This protein assay is described in which the sample is precipitated with trichloroacetic acid in the presence of sodium dodecylsulfate, filtered off on a Millipore membrane and stained with Amidoschwarz 10B, and its absorbance determined at 630 nm.
2,439 citations
TL;DR: Immunoblot analysis of Madin-Darby canine kidney cells demonstrates the presence of a polypeptide similar in molecular weight to that detected in liver, suggesting that this protein is potentially a ubiquitous component of all mammalian tight junctions.
Abstract: A tight junction-enriched membrane fraction has been used as immunogen to generate a monoclonal antiserum specific for this intercellular junction. Hybridomas were screened for their ability to both react on an immunoblot and localize to the junctional complex region on frozen sections of unfixed mouse liver. A stable hybridoma line has been isolated that secretes an antibody (R26.4C) that localizes in thin section images of isolated mouse liver plasma membranes to the points of membrane contact at the tight junction. This antibody recognizes a polypeptide of approximately 225,000 D, detectable in whole liver homogenates as well as in the tight junction-enriched membrane fraction. R26.4C localizes to the junctional complex region of a number of other epithelia, including colon, kidney, and testis, and to arterial endothelium, as assayed by immunofluorescent staining of cryostat sections of whole tissue. This antibody also stains the junctional complex region in confluent monolayers of the Madin-Darby canine kidney epithelial cell line. Immunoblot analysis of Madin-Darby canine kidney cells demonstrates the presence of a polypeptide similar in molecular weight to that detected in liver, suggesting that this protein is potentially a ubiquitous component of all mammalian tight junctions. The 225-kD tight junction-associated polypeptide is termed "ZO-1."
1,594 citations
TL;DR: The method of Lowry and coworkers combined the use of copper, as suggested by Herriott, with the Folin phenol method, which originated from the work of Wu, to produce a more reliable and sensitive protein analysis.
1,123 citations
TL;DR: The results show that the transition of glutamate from neurotransmitter to neurotoxin is facilitated when cellular energy is limited in cultured cerebellar neurons, demonstrating that glucose metabolism, ATP production, and functioning Na+,K+-ATPases are necessary to generate a resting potential sufficient to maintain the voltage-dependent Mg2+ block of the NMDA receptor channel.
1,010 citations
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Journal Article•
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.
289,852 citations
1,589 citations
101 citations
TL;DR: Two proteins present in the boar vesicular secretion known as protein A and protein H were shown to promote the swelling of the mucin to form the characteristic rigid elastic gel of boar semen.
Abstract: 1. Moving-boundary electrophoresis of the mucin from the Cowper's gland of the boar revealed a sharp single peak at pH values from 1.1 to 9.0 and an isoelectric point of 1.1. 2. Neuraminidase treatment of the mucin, which removed at least 96% of the sialic acid groups, decreased the electrophoretic mobility at pH4 from -7.4x10(-5) (for the mucin) to -0.64x10(-5)cm(2)V(-1)s(-1). 3. Ultracentrifugal sedimentation values of s(20,w) showed a marked dependence on concentration. A hyperfine peak, similar to that given by ovine submaxillary secretion, persisted throughout the run at higher concentrations. Ultracentrifugal studies further showed a very low value for the diffusion coefficient (D(20,w) -1.57x10(-8)cm(2)/s). 4. Calculation of the approximate molecular weight from comparable s(20,w) and D(20,w) values gave a provisional value of 6.5x10(6). 5. Two proteins present in the boar vesicular secretion known as protein A and protein H (the haemagglutinating protein) were shown to promote the swelling of the mucin to form the characteristic rigid elastic gel of boar semen. It is suggested that protein A molecules particularly (mol.wt. 2.8x10(4)) cross-link with the long molecules of the mucin to form the seminal gel.
38 citations
TL;DR: In semen freshly collected by means of an artificial vagina the mucin has lost its sticky character and appears as small gelatin-like lumps resembling tapioca and if the semen is left standing for several hours these lumps grow and coalesce into large masses of transparent elastic gel which may occupy more than 50 per cent of the semen volume.
Abstract: THE two bulbo-urethral glands (Cowper's glands) of the boar lie parallel to the pelvic urethra to which they are united by a heavy muscular attachment. They are normally about 15 cm long by 3–5 cm in diameter and contain a sticky, white mucin which is ejected into the pelvic urethra during ejaculation of semen. In semen freshly collected by means of an artificial vagina the mucin has lost its sticky character and appears as small gelatin-like lumps resembling tapioca. Each lump consists of a white opaque ‘nucleus’ surrounded by a water-clear gel. If the semen is left standing for several hours these lumps grow and coalesce into large masses of transparent elastic gel which may occupy more than 50 per cent of the semen volume. Many spermatozoa are trapped in the gel mass.
22 citations