Abstract: The invention relates to methods of separation and/or purification of impurities yielding a purified heterologous protein product devoid of related impurities or with substantially minimal quantities of such glycosylated impurities. More specifically, the invention relates to the identification of glycosylated forms of insulin analogues such as glargine impurities characterized post expression in yeast based systems such as Pichia pastoris. The invention also relates to methods used to clone gene encoding the protein insulin glargine; inserting the related gene in a suitable yeast host; producing culture of the recombinant strain, stimulating expression of the heterologous polypeptide, its secretion and purification post fermentation and related enzymatic conversions.

Abstract: The disclosure relates to method of reducing O-glycosylation levels of the insulin or insulin analog precursor molecule produced by Pichia sp. The present disclosure provides genetically engineered knock-out strains of methylotrophic yeast including Pichia and especially Pichia pastoris by disruption of Protein mannosyl transferase (PMT) genes and rendering them capable of producing heterologous proteins with reduced glycosylation. Vectors, which comprise coding sequences for PMT1, PMT2, PMT4, PMT5, and PMT6 genes, for transforming methylotrophic yeasts are contemplated by the present disclosure. PMT inactivated strains of this disclosure have been deposited at MTCC, Chandigarh. The strains are PMT1/GS115 (MTCC 5515), PMT4/GS115 (MTCC 5516), PMT5/GS115 (MTCC 5517) and PMT6/GS115 (MTCC 5518).

Abstract: The disclosure relates to method of reducing O-glycosylation levels of the insulin or insulin analog precursor molecule produced by Pichia sp. The present disclosure provides genetically engineered knock-out strains of methylotrophic yeast including Pichia and especially Pichia pastoris by disruption of Protein mannosyl transferase (PMT) genes and rendering them capable of producing heterologous proteins with reduced glycosylation. Vectors, which comprise coding sequences for PMT1, PMT2, PMT4, PMT5, and PMT6 genes, for transforming methylotrophic yeasts are contemplated by the present disclosure. PMT inactivated strains of this disclosure have been deposited at MTCC, Chandigarh. The strains are PMT1/GS115 (MTCC 5515), PMT4/GS115 (MTCC 5516), PMT5/GS115 (MTCC 5517) and PMT6/GS115 (MTCC 5518).

Abstract: The invention relates to methods of separation and/or purification of impurities yielding a purified heterologous protein product devoid of related impurities or with substantially minimal quantities of such glycosylated impurities. More specifically, the invention relates to the identification of glycosylated forms of insulin analogues such as glargine impurities characterized post expression in yeast based systems such as Pichia pastoris. The invention also relates to methods used to clone gene encoding the protein insulin glargine; inserting the related gene in a suitable yeast host; producing culture of the recombinant strain, stimulating expression of the heterologous polypeptide, its secretion and purification post fermentation and related enzymatic conversions.

Abstract: The invention relates, interalia, to the field of purification of peptides, notably cyclic or non-cyclic peptides their analogs or derivatives thereof. More particularly, the invention relates to a simplified and optimized purification process of cyclic peptides from a composition comprising the said peptide and at least one related impurity by chromatographic procedures enabling high yields, selectivity and purity of the desired end product. The improved process is particularly useful for the preparation of eptifibatide, exenatide, atosiban, nesiritide and their respective derivatives and analogs. The polypeptides are prepared in high purity of at least about 96%, and preferably at least about 99%.