Lipolytic substances in bovine thyroid, parotid and pineal glands

A compendium of G-protein-coupled receptors and cyclic nucleotide regulation of adipose tissue metabolism and energy expenditure

With the ever-increasing burden of obesity and Type 2 diabetes, it is generally acknowledged that there remains a need for developing new therapeutics. One potential mechanism to combat obesity is to raise energy expenditure via increasing the amount of uncoupled respiration from the mitochondria-rich brown and beige adipocytes. With the recent appreciation of thermogenic adipocytes in humans, much effort is being made to elucidate the signaling pathways that regulate the browning of adipose tissue. In this review, we focus on the ligand-receptor signaling pathways that influence the cyclic nucleotides, cAMP and cGMP, in adipocytes. We chose to focus on G-protein-coupled receptor (GPCR), guanylyl cyclase and phosphodiesterase regulation of adipocytes because they are the targets of a large proportion of all currently available therapeutics. Furthermore, there is a large overlap in their signaling pathways, as signaling events that raise cAMP or cGMP generally increase adipocyte lipolysis and cause changes that are commonly referred to as browning: increasing mitochondrial biogenesis, uncoupling protein 1 (UCP1) expression and respiration.

Observations on the lipolytic and melanotropic properties of neurophysin proteins

Previous work indicated that brain contains 3 types of lipolytic-melanotropic peptide: (1) in adenohypophysis: ACTH, alpha-MSH, beta-MSH, peptide I, peptide L', beta-lipotropin and gamma-lipotropin; (2) in neurohypophysis: peptide 7D6, also termed neurophysin I, peptide II or Wuu-Saffran peptide; (3) in extrahypophyseal regions: peptide IIF. Bovine and human neurophysin I prepared by R. Walter has now been found devoid of lipolytic and melanotropic activities. Porcine and bovine peptide 7D6, closely similar or identical to bovine neurophysin I in electrophoretic mobility and amino acid composition, were therefore reexamined to determine whether their lipolytic-melanotropic property resided in a contaminating factor. When peptide 7D6 was analyzed in 100 transfer counter current distribution (1 butanol/0.1M NH4 HCO3), the neurophysin was recovered in tubes 1-9 (7D6-alpha) representing 95% of 7D6. 7D6-alpha was inactive in lipolytic and melanotropic assays. The biologic activities of 7D6 were recovered instead in tubes 50-70 (labeled 7D6-beta), representing 5% of 7D6. 7D6-beta proved to be a peptide with MW 1000-3000, closely similar to peptide IIF in amino acid composition, MW, and Rf values in 4 systems of paper chromatography.

Isolation of a novel glycoprotein from the urine of a patient with chronic myelocytic leukemia

Patient B. J. with chronic myelocytic leukemia excreted 0.5-1.1 g protein per day in the urine. Gel filtration on Sephadex G-75 showed about one-third of this protein to be in molecular weight range 20,000-40,000 (fraction BJC). BJC, prepared from 9 liters of urine by gel filtration, was chromatographed on carboxymethylcellulose. Two proteins were eluted from the resin in pure form (as shown by zone and immunoelectrophoresis) in yields representing 8 and 3 mg/liter of urine: BJC1 and BJC2. Their amino acid compositions were identical. BJC1 contained 61% carbohydrate (33% hexose, 11% sialic acid, 13% glucosamine, 5% galactosamine). BJC2 contained one-fourth to one-half as much of each carbohydrate. Molecular weight of BJC1 was estimated at 29,000 by gel filtration. Neither glycoprotein reacted with rabbit antiserum to normal human serum.Antiserum to BJC1 was made in the rabbit. Immunoelectrophoresis with this antiserum showed a faint precipitin line, corresponding in mobility to BJC1, in normal human plasma, and a stronger line in most leukemic plasmas. By immunodiffusion, BJC1 was not detectable in normal human urine, but a positive reaction occurred in the following conditions: leukemia, 64-72%; other types of disseminated neoplastic disease, 36-78%; regional ileitis, 45%; ulcerative colitis, 38%; tuberculosis, 33%; during the 1st wk after major surgery, 33%.BJC2 was found in the urine by immunoelectrophoresis in 10% of patients with neoplastic disease and was not observed in urine of other patients or in human plasma. Amino acid composition, carbohydrate content, and antigenic specificity indicate BJC1 is a previously unrecognized member of the system of normal human plasma glycoproteins. Like certain other glycoproteins, its plasma concentration frequently increases in patients with neoplastic disease, chronic inflammatory disease, or tuberculosis and after surgery. Because molecular weight is 29,000, increased plasma concentration readily causes its appearance in the urine.