Modified Factor IX Polypeptides Enhancing Procoagulant Activity
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Solution Overview
Problem
Current Factor IX polypeptides used for treating hemophilia B and thrombolytic diseases have limitations in terms of stability and therapeutic efficacy, particularly in maintaining procoagulant activity.
Innovation Solution
Modified Factor IX polypeptides with specific amino acid replacements, such as R318Y, R318E, and R318F, and additional modifications like glycosylation site introductions or eliminations, are developed to enhance procoagulant activity and stability, thereby improving therapeutic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If unmodified FIX polypeptides are used for treatment, then the therapeutic approach is simple, but the procoagulant activity and stability are insufficient
Solution Approach 1:
The patent applies parameter changes by modifying specific amino acid residues in the FIX polypeptide sequence. Mutations at positions 318, 338, and 403 (e.g., R318Y, R338E, K403E) alter the molecular properties of the polypeptide to enhance procoagulant activity and stability without completely redesigning the overall structure.
Solution Approach 2:
The patent creates composite structures by combining multiple modifications in a single FIX polypeptide molecule. The polypeptide integrates specific amino acid replacements at multiple positions, along with introduced glycosylation sites, to produce a enhanced therapeutic agent that combines several functional improvements.
2Reliability
If FIX polypeptides are modified to increase procoagulant activity, then therapeutic efficacy is improved, but the complexity of production and characterization increases
Solution Approach 1:
The patent modifies production parameters by making targeted amino acid substitutions that can be incorporated during recombinant expression. The specific mutations (e.g., at positions 318, 338, 403) are designed to be compatible with standard recombinant protein production methods while enhancing therapeutic properties.
Solution Approach 2:
The patent applies local quality changes by introducing modifications at specific, localized positions within the FIX polypeptide sequence rather than throughout the entire molecule. The amino acid replacements are concentrated at particular residues (318, 338, 403) and specific glycosylation sites are introduced at selected Asn residues, allowing enhanced function with controlled complexity.
3Duration of action of stationary object
If glycosylation sites are introduced to extend plasma half-life, then stability is improved, but the structural complexity increases
Solution Approach 1:
The patent changes structural parameters by introducing glycosylation sites at specific Asn residues (e.g., positions 157, 167, 264, 346) in the FIX polypeptide sequence. These modifications alter the molecular properties to enhance plasma stability and extend half-life while maintaining a relatively controlled level of structural complexity through selective site introduction.
Data Source
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AI summary
Modified Factor IX (FIX) polypeptides and uses thereof are provided. Such modified FIX polypeptides include FIXa and other forms of FIX. Among the modified FIX polypeptides provided are those that have altered activities, typically altered procoagulant activity, including increased procoagulant activities. Hence, such modified polypeptides are therapeutics.