Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1996-11-29
pubmed:abstractText
Many hormones circulate bound to serum proteins that modulate ligand bioactivity and bioavailability. To understand the biology of leptin action, we investigated the presence of leptin binding proteins in serum. 125I-labeled leptin binds competitively to at least three serum macromolecules with molecular masses of approximately 85, approximately 176, and approximately 240 kDa in rodents and approximately 176 and approximately 240 kDa in humans. The ability to bind appears to involve sulfhydryl/disulfide interactions because it is inhibited under reducing conditions. When serum is added to recombinant 125I-leptin, there is a shift in sedimentation of 125I-leptin as analyzed by sucrose gradient centrifugation from approximately S1.9 to approximately S4.3. This shift is markedly attenuated in serum from obese mice (ob/ob, db/db, brown-fat ablated, gold-thioglucose treated, high-fat fed) compared with that from nonobese controls. The size distribution of endogenous serum leptin as determined by radioimmunoassay (RIA) after sucrose gradient centrifugation is also consistent with saturation of binding in hyperleptinemic obesity. In humans, free leptin increases with BMI. Thus, in lean rodents and humans a large proportion of leptin circulates bound to several serum proteins. Free leptin is increased in serum of obese subjects, which may alter leptin bioactivity, transport, and/or clearance.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1638-43
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8866573-Adult, pubmed-meshheading:8866573-Aged, pubmed-meshheading:8866573-Animals, pubmed-meshheading:8866573-Aurothioglucose, pubmed-meshheading:8866573-Blood Proteins, pubmed-meshheading:8866573-Diabetes Mellitus, pubmed-meshheading:8866573-Diabetes Mellitus, Type 2, pubmed-meshheading:8866573-Dietary Fats, pubmed-meshheading:8866573-European Continental Ancestry Group, pubmed-meshheading:8866573-Female, pubmed-meshheading:8866573-Humans, pubmed-meshheading:8866573-Leptin, pubmed-meshheading:8866573-Male, pubmed-meshheading:8866573-Mice, pubmed-meshheading:8866573-Mice, Obese, pubmed-meshheading:8866573-Middle Aged, pubmed-meshheading:8866573-Obesity, pubmed-meshheading:8866573-Obesity, Morbid, pubmed-meshheading:8866573-Protein Binding, pubmed-meshheading:8866573-Proteins, pubmed-meshheading:8866573-Radioimmunoassay, pubmed-meshheading:8866573-Reference Values
pubmed:year
1996
pubmed:articleTitle
Evidence for leptin binding to proteins in serum of rodents and humans: modulation with obesity.
pubmed:affiliation
Department of Medicine at Harvard Medical School, Beth Israel Hospital, Boston, Massachusetts, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't