Treatments Which Alleviate Functional Glycosylated Leptin Transport Factor for Controlling Weight and Obesity

摘要

Methods and compounds for treating obesity and inducing weight loss use a functional, glycosylated leptin transport factor (LTF) polypeptide, referred to as fn/glyLTF. An unstable defective version of the LTF protein, referred to herein as def/LTF, is present in freshly-drawn blood from obese animals or people; it is degraded rapidly in circulating blood. In people with normal body weight, fn/glyLTF stabilizes and protects leptin, a hormone with powerful effects on fat metabolism and body mass. LTF apparently is the same protein previously recognized as a soluble truncated fragment of the obesity receptor (Ob-R) protein, referred to in the prior art as Ob-Re, or sOb-R. In humans with normal body weight, fn/glyLTF has a weight of about 145 kD, compared to a polypeptide-only weight of about 93 kD. defLTF has a substantially lower molecular weight, and tests using deglycosylating enzymes indicate that it is not glycosylated to the same level as fn/glyLTF. Treatment methods include: (1) elevating concentrations of fn/glyLTF in circulating blood, by means such as intravenous injection or sustained-release implants, or by gene therapy; (2) suppressing enzymatic deglycosylation in circulating blood, such as by extracorporeal removal of deglycosylating enzymes; and, (3) providing “surrogate” forms of fn/glyLTF. Diagnostic kits are also disclosed, for measuring both fn/glyLTF and def/LTF in animals and people suffering from obesity.