The present disclosure provides compositions for regulating glucose metabolism. The compositions provide for reduced levels of p75.sup.NTR and/or reduced binding of p75.sup.NTR to a GTPase such as Rab31 or Rab5. The compositions are useful in methods of regulating glucose metabolism, which methods are also provided.

A method for determining the activity of Rab escort protein 1 (REP1) comprising the steps: (a) providing a sample comprising REP1; (b) contacting the sample of step (a) with Rab6a, Rab geranylgeranyltransferase (Rab GGTase) and a lipid donor substrate; and (c) detecting the lipidated Rab6a product.

The present invention discloses a methionine adenosyltransferase (MAT) activity assay method and a kit for measuring MAT activity. A sample and relevant reagents are mixed in certain way that MAT-catalyzed reaction occurs efficiently. The reaction and the competitive ELISA that quantifies the product S-adenosylmethionine (SAM) are carried out simultaneously. The MAT activity is calculated as the amount of SAM produced per unit time. SAM is calculated through spectral absorbance of the SAM produced and comparing it to that of the standard. The method of SAM quantification is via tracer-labelled anti-SAM antibody or SAM (or SAM analog) antigen through competitive ELISA, so that the produced SAM competes with the SAM antigen for binding anti-SAM antibody. The method and the kit described in the present invention are more sensitive, accurate, reliable, straightforward, easier and faster. The method was used to measure the MAT activities of normal and cancerous liver cells.

Method for the detection of glutamine and its analogues are provided by the present disclosure. Also provided are methods for measuring the levels of glutamine and its analogues, including diagnostic methods. Further provided are methods that utilise glutamine analogues for the synthesis of coloured pigments and other useful agents. The methods comprise the use of a nonribosomal peptide synthetase (NRPS) under conditions to produce an indigoidine or indigoidine-related pigment.

The invention refers to a method for diagnosing an individual who is to be subjected to or is being subjected to an anti-tumor necrosis factor alpha (TNF or TNF) treatment to assess the responsiveness to an anti-TNF treatment which comprises the detection of immunoglobulin(s) against one or more biomarker proteins in a bodily fluid or an excrement of said patient, and sorting the individual into one of two categories based on detection of said immunoglobulin(s), wherein individuals are classified as NON-responder or responder. The invention refers to diagnostic kits comprising said one or more biomarker proteins and the use of these kits for assessing the responsiveness to an anti-TNF treatment of an individual who is to be subjected to or is being subjected to an anti-TNF treatment.

In this invention, cell lines are created for enzyme inhibitory testing of inhibitors against Plasmodium falciparum DHFR-TS and HPPK-DHPS. Provided the complementing DHFR-TS and HPPK-DHPS have sufficient activities to support growth of the surrogates in un-supplemented medium, the same surrogates could be used for screening inhibitors of targets against other parasite and pathogen species e.g. Plasmodium vivax, Trypanosoma brucei, Trypanosoma cruzi, Toxoplasma gondii or Mycobacterium tuberculosis. The cell lines in this invention are Escherichia coli strain whose thyA, folA, folK, and folP genes were disrupted using genetic knockout coupled with elimination of antibiotic resistance markers. The thyA KO, folP KO, folK KO, thyAfolA KO, folKfolP KO, thyAfolAfolP KO, thyAfolAfolK KO and thyAfolAfolKfolP KO E. coli cell lines are easy and convenient for testing single and combination drugs as plasmids bearing complementing parasite genes can be introduced simply by transformation using standard antibiotic selection.

Method for the detection of glutamine and its analogs are provided by the present disclosure. Also provided are methods for measuring the levels of glutamine and its analogs, including diagnostic methods. Further provided are methods that utilize glutamine analogs for the synthesis of colored pigments and other useful agents. The methods comprise the use of a nonribosomal peptide synthetase (NRPS) under conditions to produce an indigoidine or indigoidine-related pigment.

Methods for measuring REP-1 and REP-2 activity are provided. In certain embodiments, a method includes: (a) contacting cells that do not express endogenous functional REP-1 or REP-2 protein with an adeno-associated viral (AAV) vector comprising a CHM gene encoding a REP-1 protein or CHM like gene encoding a REP-2 protein under conditions allowing cell transduction; (b) incubating transduced cells under conditions allowing expression of the encoded REP-1 or REP-2 protein; (c) lysing the transduced cells to produce an extract comprising the encoded REP-1 or REP-2 protein and Rab small GTPase (Rabs); (d) incubating said extract with a Rab substrate for a period of time and under conditions allowing prenylation of the Rab thereby forming prenylated Rab; and (e) detecting and/or quantifying the prenylated Rab, wherein the amount of prenylated Rab reflects REP-1 or REP-2 activity thereby measuring REP-1 or REP-2 activity.

The invention refers to a method for diagnosing an individual who is to be subjected to or is being subjected to an anti-tumor necrosis factor alpha (TNF or TNF) treatment to asses the responsiveness to an anti-TNF treatment which comprises the detection of immunoglobulin(s) against one or more biomarker proteins in a bodily fluid or an excrement of said patient, and sorting the individual into one of two categories based on detection of said immunoglobulin(s), wherein individuals are classified as NON-responder or responder. The invention refers to diagnostic kits comprising said one or more biomarker proteins and the use of these kits for assessing the responsiveness to an anti-TNF treatment of an individual who is to be subjected to or is being subjected to an anti-TNF treatment.

The present disclosure provides compositions for regulating glucose metabolism. The compositions provide for reduced levels of p75.sup.NTR and/or reduced binding of p75.sup.NTR to a GTPase such as Rab31 or Rab5. The compositions are useful in methods of regulating glucose metabolism, which methods are also provided.