DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/18/2025 has been entered.
Claim Status
The amendment of 11/18/2025 has been entered. Claims 1-4, 6-7, and 9-32 are pending in this US patent application. Claims 26-32 remain withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, and claims 14-15 remain withdrawn as being directed to a nonelected species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 08/13/2024.
Claims 1-4, 6-7, 9-13, and 16-25 are currently under examination and were examined on their merits.
Election/Restrictions
Upon further search and consideration, the Examiner has rejoined the species of E. coli hydrogenase 2 recited in part ii) of claim 11 with the species of E. coli hydrogenase 1 and the R. eutropha hydrogenases of parts iii) and iv) of claim 11 for the genus of “first polypeptide.”
Information Disclosure Statement
The information disclosure statement filed in this application on 11/18/2025 has been received and considered.
Withdrawn Rejections
All rejections of claim 8 set forth in the previous Office action are withdrawn in light of the amendment of 11/18/2025, which canceled claim 8.
The rejection of claim 6 under 35 U.S.C. 112(b) as being indefinite for depending from a canceled claim as set forth in the previous Office action is withdrawn in light of the amendment of 11/18/2025, which amended claim 6 to depend from claim 1.
The rejections of the claims under 35 U.S.C. 103 as being unpatentable over Winkler in view of Lauterbach as set forth in the previous Office action are withdrawn in favor of the new rejections presented below.
Claim Interpretation
Applicant has added limitations to the instant claims regarding the actions that the polypeptide automatically takes when performing the positively recited steps in the method of claim 1. The positively recited steps of claim 1, i.e., the steps performed by a person practicing the method, are “contacting an oxidized flavin cofactor and molecular hydrogen…or an isotope thereof with a first polypeptide which is a hydrogenase enzyme…under conditions such that the oxidized flavin cofactor is reduced to form a reduced flavin cofactor” and “contacting the reduced flavin cofactor and a reactant with a second polypeptide which is an oxidoreductase.” Similar limitations have been added to instant claim 2. The means by which electrons are transferred by the polypeptide from the molecular hydrogen to the oxidized flavin cofactor, whether direct transfer or any indirect transfer allowed by the ingredients present in the reaction mixture, which are not limited in Applicant’s open-ended “comprising” claims, are inherent results of the steps of contacting. A clause in a method claim does not receive weight when it simply recites the intended result of a process step positively recited. See MPEP § 2111.04(I). As such, any prior art that teaches the positively recited steps of claims 1-2 will be interpreted to read on the entirety of claims 1-2, whether or not the prior art teaches the specific direct electron transfer recited in the claims.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4, 6-7, 9-13, 16-22, and 24-25 are rejected under 35 U.S.C. 103 as being unpatentable over Winkler et al., J. Biotechnol. 162: 381-389 (2012; cited on the IDS filed 04/13/2023), in view of Reeve et al., Chem. Commun. 48: 1589-1591 (2012; cited on the IDS filed 11/18/2025).
Winkler teaches the use of ene-reductase enzymes in asymmetric synthesis (see entire document, including page 381, right column, paragraph 1). Figure 1 shows that ene-reductases use a reduced flavin cofactor to catalyze asymmetric bioreduction reactions, resulting in the production of a reduced reaction product and an oxidized flavin cofactor. The oxidized flavin cofactor is recycled to the reduced flavin cofactor by a cofactor recycling system that reduces NAD(P)+ to NAD(P)H by use of a dehydrogenase enzyme. The NAD(P)H then reduces the oxidized flavin cofactor, allowing for additional rounds of catalysis. The cofactor recycling enzymes can include enzymes such as formate dehydrogenase, alcohol dehydrogenase, glucose dehydrogenase, glucose 6-phosphate dehydrogenase, and phosphite dehydrogenase (page 382, Figure 1; cf. parts (i) and (ii) of claims 1-2; cf. claims 3-4, 12-13, and 16-19; see above under Claim Interpretation for the Examiner’s interpretation of the intended result clauses in claims 1-2). The ene-reductase and cofactor recycling system can be used in one-pot enzymatic cascades (page 385, left column, paragraph 1; cf. claims 1-2, 20, and 22; the Examiner notes that reacting the ene-reductase and the cofactor recycling enzymes in one pot necessarily involves the contact of all enzymes, substrates, and cofactors as recited in claims 1-2, which can also be interpreted as the ene-reductase and the recycling enzyme being “attached together” as recited in instant claim 22 because there is no requirement for how long the polypeptides must remain attached in claim 22).
However, Winkler does not teach that the enzyme in the cofactor recycling enzyme is an enzyme that meets the requirements of the first polypeptide recited in instant claim 1.
Reeve teaches that regeneration systems for NAD cofactors are required for many industrial biocatalysis applications and that enzyme-based regeneration systems, such as formate dehydrogenase, are used for this purpose (see entire document, including page 1589). However, linking cofactor regeneration to the H+/H2 couple, such as by using the soluble hydrogenase (SH) from R. eutropha, is attractive because it simplifies the separation of desired products (page 1589, left column, paragraph 3, to right column, paragraph 1). The NAD+-reducing subunit of SH was purified separately and adsorbed onto pyrolytic graphite particles along with more stable hydrogenases (page 1589, right column, paragraph 3). E. coli hydrogenase 2, which is capable of bidirectional cofactor recycling, and the R. eutropha membrane bound hydrogenase, an [NiFe]-hydrogenase that maintains greater activity in the presence of O2 and enables NADH generation in the presence of oxygen, were both immobilized on the graphite particles with HoxFU and used for NAD cofactor regeneration in enzyme coupled assays at room temperature (page 1590, left column, paragraph 2, through right column, paragraph 2; page 1591, left column, paragraph 2, to right column, paragraph 1; cf. part (i) of claims 1-2; cf. claims 3, 6-7, 9-11, 21, and 24-25).
While Winkler does not teach the use of one of the immobilized hydrogenases taught by Reeve as the enzyme in the cofactor recycling system for use in industrial synthesis processes using ene-reductase enzymes, it would have been obvious to one of ordinary skill in the art to do so under the conditions taught by Reeve because Reeve teaches the use of E. coli hydrogenase 2 and R. eutropha O2-tolerant hydrogenases in cofactor recycling systems in enzyme coupled assays and that the use of these enzymes simplifies the separation of the desired products as compared to the recycling enzymes taught by Winkler. One of ordinary skill in the art would have a reasonable expectation that using the enzymes of Reeve under the conditions taught by Reeve in the cofactor recycling system for use in the industrial ene-reductase processes of Winkler would successfully result in the synthesis of the desired ene-reductase products without needing to separate byproducts from the cofactor recycling enzyme.
Therefore, claims 1-4, 6-7, 9-13, 16-22, and 24-25 are rendered obvious by Winkler in view of Reeve and are rejected under 35 U.S.C. 103.
Claims 1-4, 6-7, 9-13, and 16-25 are rejected under 35 U.S.C. 103 as being unpatentable over Winkler et al., J. Biotechnol. 162: 381-389 (2012; cited on the IDS filed 04/13/2023), in view of Reeve et al., Chem. Commun. 48: 1589-1591 (2012; cited on the IDS filed 11/18/2025), and Lauterbach et al., FEBS J. 280: 3058-3068 (2013; cited on the IDS filed 04/13/2023).
As discussed above, claims 1-4, 6-7, 9-13, 16-22, and 24-25 are rendered obvious by Winkler in view of Reeve. However, these references do not teach the presence of the enzymes in biological cells as recited in instant claim 23.
Lauterbach teaches enzymes for the recycling of NAD(P)H in industrially relevant processes (see entire document, including page 3058, left column, paragraph 1). Particular hydrogenases noted by Lauterbach as being useful as cofactor recycling enzymes include the O2-tolerant membrane-bound hydrogenase from R. eutropha (page 3061, Figure 2; cf. claims 8-11). The hydrogenases can be immobilized onto solid supports or used in whole cells (page 3064, left column, paragraph 2, to right column, paragraph 3; cf. claim 23).
While Winkler and Reeve do not teach the use of the cofactor recycling enzymes in whole cells as recited in instant claim 23, it would have been obvious to one of ordinary skill in the art to do so because Lauterbach teaches that hydrogenases used for cofactor recycling in industrially relevant processes can be used within whole cells. One of ordinary skill in the art would have a reasonable expectation that practicing the method of recycling cofactors for ene-reductase processes as taught by Winkler with the hydrogenases of Reeve inside of the whole cells of Lauterbach would successfully result in the synthesis of desired ene-reductase products.
Therefore, claims 1-4, 6-7, 9-13, and 16-25 are rendered obvious by Winkler in view of Reeve and Lauterbach and are rejected under 35 U.S.C. 103.
The Supreme Court has acknowledged:
When a work is available in one field of endeavor, design incentives and other market forces can prompt variations of it, either in the same field or a different one. If a person of ordinary skill can implement a predictable variation…103 likely bars its patentability…if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond that person’s skill. A court must ask whether the improvement is more than the predictable use of prior-art elements according to their established functions……the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results (see KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 U.S. 2007) (emphasis added).
From the teachings of the references, it is apparent that one of ordinary skill in the art would have had a reasonable expectation of success in producing the claimed invention. Therefore, the invention as a whole was prima facie obvious to one of ordinary skill in the art at the time the invention was made, as evidenced by the references, especially in the absence of evidence to the contrary.
Response to Arguments
Applicant has traversed the previous rejection of the claims under 35 U.S.C. 103 as being unpatentable over Winkler in view of Lauterbach. In support of Applicant’s arguments, Applicant has submitted the Declaration of Holly Reeve, filed 11/18/2025. Both Applicant’s and Declarant’s arguments are directed to the use of the enzymes of Lauterbach in the ene-reductase cofactor recycling process of Winkler. However, that particular combination of references is not relied upon in the instant rejection. As such, Applicant’s and Declarant’s arguments are moot, and the Examiner has maintained the rejections presented above.
Conclusion
No claims are allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Erin M. Bowers, whose telephone number is (571)272-2897. The examiner can normally be reached Monday-Friday, 7:30-5:00.
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/Erin M. Bowers/Primary Examiner, Art Unit 1653 12/04/2025