type obj values by enum keys (TS)

Question

I have an object with 2 types of values: str and num. I want to type all properties without duplicating of type name.

const obj: any = {
  num1: number;
  num2: number;
  ...
  numN: number;

  str1: string;
  str2: string;
  ...
  strN: string;
}

I expect to see the next results of types tests:

const obj: TObj = {
  num1: 1,   // ok
  num2: '2', // error

  str1: '1'  // ok
  str2: 2    // error 
};

I think the answer lies next to the following pseudotype:

type TObj = {
  [key in NumKeys]: number;
  [key in StrKeys]: string;
};

UPD Partly, I achieved the goal by creating enums for iterating.

enum NumKeys {
  num1 = 'num1',
  num2 = 'num2',
  ...
  numN = 'numN',
}

enum StrKeys {
  str1 = 'str1',
  str2 = 'str2',
  ...
  strN = 'strN',
}

Then I created 2 temporary types for each of those.

type TNumObj = {
  [key in NumKeys]: number;
};

type TStrObj = {
  [key in StrKeys]: string;
};

Finally, I combined them to achieve the goal.

const obj: TNumObj & TStrObj = {
  num1: 1,
  num2: 2,
  ...
  numN: N,

  str1: '1',
  str2: '2',
  ...
  strN: 'N',
};

The annoying part of the answer is duplicating the same text in each key-value pair of the enum object.

enum NumKeys {
  num1 = 'num1',
  num2 = 'num2',
  ...
  numN = 'numN',
}

Is there some simple way to create a such structure without duplicating?